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Mozley SuperPanner: Laboratory Mineral Separator Table
Rapid separation of mineral grains for mineralogists, metallurgists and mill operators. The 911C800 Laboratory Mineral Separator is a valuable tool for metallurgists, mineralogists and mill operators. It quickly and efficiently separates mineral grains of close specific gravity.
The Superpanner is a Mechanism invented by Professor H. T. Haultain which simulates rocking,bumping, and sluicing action used in panning, and gives precise information as to possibility of gravity treatment of sands. Used in rapid assays and as a research aid.
Tabling tests can begin with individual treatment of each size from about 50 mesh down to, say, 20um on a Haultain superpanner. If material can be concentrated by gravity methods (tabling, vanning, and spiralling included), it can be concentrated on a superpanner. If this instrument fails, no commercial method will succeed on fine sizes. The super-panner is a miniature shaking table into which are built most, if not all, of the motions used in panning. A sample of a few grams can be tested, or some hundreds of grams can be worked in successive additions and particle removals. There is, in fact, no great virtue in using more than a light charge when testing for a gravity process, but bigger quantities are treated when search is being made for particles of heavy minerals only present in very small amounts. The advantage to the microscopist of being able to examine a sample of, say, half a gram which should contain all the heavier minerals from a total of half a kilogram are obvious. Any desired texture of decking can be used on the superpanner, linoleum and stainless steel being sufficient for most work. Adjustments are for side and end shake. slope, bump, stroke length and speed, and sluicing water.
A most effective instrument and it has always been a puzzle to me that it is not been universally used by millmen.
Description
It incorporates an improved shaking mechanism and a non-porous deck through which a cyclic pulse of jigged water is applied, thus stratifying the test material. If superpanner tests are favourable, a suitably classified feed is run over a miniature shaking table. The usual settings for a commercial machine are applied, attention being given to rate of feed and to pulp consistency.
Typical Applications
The separator is supplied with two easily interchangeable stainless-steel trays enabling efficient separation over a wide size range.
The ‘V’ profile tray with ‘end knock’, when treating closely sized material, is capable of not only of duplicating heavy liquid analysis results, but of giving additional data in the higher SG ranges. The separator is therefore ideally suited to carrying out release analysis.
The ‘V’ profile tray with ‘end knock’ is able to accurately predict sand table performance when treating hydraulically classified products.
This is of great value in optimization of plant performance.
The flat tray is capable of making very efficient separations of samples finer than 100 microns. This is of value in predicting slime table
performance or carrying out release analysis where fineness of the material precludes heavy liquid analysis.
Applications
- Gold
- Silver
- Platinum
- Cassiterite/Tin
- Tantalite/Tantalum
- Wolframite
- Scheelite
- Metal-bearing sulfides
- Zirconium
- Titanium minerals
- Chromite
- REE
Grade/Recovery Analysis of the Laboratory Mineral Separator Table
Interpretation of test data may be carried out visually, microscopically or by assay analysis of the separator products. If a complete grade versus recovery evaluation is required a series of consecutive samples is collected during the separation. At the completion of the run of the product remaining on the tray is divided into middlings and concentrate to be collected separately. All samples are dried, weighed and assayed and a grade versus recovery curve plotted from the results.
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“V” Profile Tray with END KNOCK | |
| For separations in the 2 mm to 100 |
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| Typical separation of coarse sample on ‘V’ profile tray: A 50 to 100g sample is placed on the tray and wetted. The cyclic motion mobilises the mineral particles enabling stratification to take place. The heavy (usually valuable) mineral settles and is ‘thrown’ upstream by the ‘end-knock’ action. The lighter (usually gangue) mineral is carried downstream by the flow of irrigation water to discharge via the tailings launder. | |
Partial separation after ½ minute
Complete separation after 3 minutesFLAT TRAY SuperPanner | |
 Sample in slurry form placed on tray | For separations in the 100 to 10 |
 Partial separation after 1 minute | |
 Complete separation after 5 minutes | |
| Typical separation of fine sample on flat tray: A 100g sample is dispersed in water in a beaker and poured onto the tray. The cyclic motion mobilises the mineral particles which spread out into a thin layer. Stratification occurs enabling the heavy (usually valuable) mineral to sink to the tray surface and be retained. The lighter (usually gangue) mineral is carried downstream by the flow of irrigation water to discharge via the tailings launder. | |
Working Principle of the Richard Mozley Table
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Superpanner Working Principle
Laboratory Mozley Mineral Separator Experiment
The Superpanner took form as illustrated in Figures 1 and 2. The essential features are a suitably supported pan of special shape, 30 inches long and 10 inches wide, and a mechanism which permits of many adjustments being quickly and readily made while in operation. The pan is a sheet of aluminium, to which has been firmly cemented a special linoleum made for me, after considerable experimentation.
This pan is bent with a gradually decreasing radius of curvature. The mechanism provides an end bump, like the old Gilpin County bumper, and a gentle side shake. The mechanism permits of the following adjustments:
- The slope of the pan
- The intensity of the end bump
- The length of stroke accompanying the end bump
- The number of strokes per minute
- The amplitude of the side shake separately for each end of the pan
- The number of oscillations per minute
- The amount of wash-water
- The depth of the pool in the rear end of the pan
This sounds very complicated, but the adjustments are very easily made while operating, and generally only three of them are much used, namely, the slope of the pan, the speed of the end bump, and the speed of the side motion.
The principle of operation is that the end bump tends to move forward the mass of sands on the pan, while the wash-water and the side motion tend to wash the surface particles to the lower end. The heavier concentrates, finding their way to the surface of the pan, come to a fine tip, where they can be removed by means of a small suction pipette. The excess water and tailings are removed by continuous suction through the tube at the lower end of the pan. A bottle is interposed in this suction so that the tailings can be collected without loss. The position of the suction tube governs the depth of pool in the lower end of the pan, which is generally reduced as the process continues. The mechanism is driven by two small independent electric motors, each with its own rheostat. One operates the end bump and the other the side motion, so these two are kept independent of each other. In the latest form of Superpanner, simple air motors take the place of the electric motors.
A really essential feature of the operation is the human element and the development of the necessary technique. As changes are made in the adjustments, the results show quickly on the pan and the operator soon realizes how to get the desired results.
There are three types of results obtainable:
- The recovery of very minute quantities of concentrates, such as free gold or tellurides. Free gold can be found in all the tailings from the Kirkland Lake district, even after intense cyanide treatment. Tellurides, when existing in the proportion of one part in ten-million, are readily recovered. The osmiridium of the Rand banket, existing in probably less than one part in fifty-million, can also be recovered.
- The recovery of a larger amount of clean concentrates, such as pyrite free from tellurides and free gold, or galena from a mixture of zinc-lead middlings, or the separation of pyrite from arsenopyrite.
- The separation of gangue from sulphides, that is, the recovery of clean tailings, for example, from flotation tailings.
The range of sizes that can be treated is from 65-mesh down to 14 microns. In some work, still finer material can be treated, especially if the feed has been sized by the Infrasizer. Simple separations can be completed in a few minutes. When dealing with extremely fine material an hour or more may be required, but the Superpanner may be left to run itself after adjustment. The paper entitled Milling Investigations into the Ore as Occurring at the Lake Shore Mines, by Blomfield and his Staff, states:
The Superpanner produces good quantitative results down to at least 14 microns and occasionally to 10, and qualitative results on all sizes.
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| Fine & coarse table feeds from tin plant | Cassiterite bearing beach sand | ‘Slime’ product from tin plant |
Description of Mozley Mineral Separator: For the pre-concentration of heavy minerals use of flowing film concentration units like tables spirals/richert cones etc. is becoming inevitable. In selection and sizing of such units use of Mozley Mineral Separator plays a vital role, since it separates mineral grains having close size ranges or specific gravities efficiently and depicts the influence of operating and design parameters in true sense.
The Laboratory Mozley Mineral Separator is capable of treating particles from 2mm to 100µm particles arc generally treated on ‘V’ profile tray and less than 100µm size particles arc treated on flat tray.
Since it is laboratory-testing device, it is having batch process. It is an extremely useful tool for rapid, testing of amenability of ore minerals for their bencficiation using flowing film devices on small scale. The plant size separators can be upstaged from the data generated. The operating principle is however incorporated into a plant-size of the machine.
Material Preparation: About 300 kg Beach Sand was collected. The collected sample was sampled to reduce its bulk to 100gms using Jones Riffler, from which about 30 packets each weighing 100gm was obtained. Feed characterization studies on this sample was performed by conducting size analysis and size-wise sink-float analysis. The results of the size analysis tests are given Table 2.
Experimental Set-up: The Laboratory Mozley Mineral Separator is capable of treating particles from 2mm to 100µm particles are generally treated on ‘V’ profile tray and less than 100µm size particles are treated on flat tray. However for the present case flat type of tray was selected for the experimental work. This tray is nothing but a stainless steel flat surface inclined at a shallow angle to the horizontal in the longitudinal direction. The tray is oscillated horizontally in a direction of 90° to the maximum slope, crank driven via pulleys by motor. Separation of particles is carried out after placing the wetted sample on the tray near upstream end. On starting the separator the sample collects into a narrow band along the apex of the flat tray. The particles are kept in motion by the action of the separator. High-density particles sink to the tray surface and are thrown towards the upstream end of the tray by the knocking action. Low-density particles are carried down the tray by the flow of irrigation water to discharge via the launder.
Experimental Procedure: To start with, slurry of 100 gm sample was prepared in a 250 ml beaker and the same was pored on to the deck after fixing the levels of the variables at desired levels. Amplitude of 3.5 inches, number strokes of 100 strokes/per minute and inclination of 1.15° were kept constant in all these experiments where as the irrigation water level was changed at four levels (of 2.0, 2.2, 2.6 and 2.8 litres/minute) while performing experiments. For each level of water flow rate, influence of oscillation/retention time varied at four levels of 1, 2, 3 and 4 minutes was studied. Thus a total 16 experiments were performed in the present study. For each experiment, concentrate (remaining on the deck) and the tailing (flown out of the tray) were collected at the end of the desired oscillation time intervals fixed. These samples were later dried, weighed and used for the analysis purpose. Further, for each of the concentrate and tailing samples thus obtained after experimentation sink-float analysis tests were performed using Bromoform as the heavy liquid. These results are used for the performance analysis of the separator in terms of misplacements, which are discussed in the subsequent headlines.
Results and discussions: The results obtained from the tests performed on Beach Sands using Mozley Mineral separator are tabulated in Table 3. The following are the important discussions that can be made on these results.
1. Fig. 1 has been plotted to illustrate the effect of time on yield of concentrate (minerals material remained on the deck), it can be noted that as the time given for oscillation of deck (at a fixed inclination and amplitude) increases, the yield of concentrate decreases almost linearly. However, the rate of decrease in yield of product is dependent of the level of the water flowrate maintained at that instant. Observing the steepness of the curves, it is to be noted that with increased water flowrate (from 2.0 lpm to 2.8 lpm) the steepness of the plots plotted increases correspondingly. This is evidenced from the slope of the lines in Fig. 1.
2. Fig. 2 is plotted to depict the quantum of lighter fraction of feed material that is pure sand reporting to reject stream selectively. For this analysis, the reject (and concentrate) product of the Mozley Separator obtained at different time intervals of collection were subjected to sink-float analysis using an organic liquid (Bromoform sp. gr. 2.9). The float and sink fractions thus obtained after float sink analysis were used to represent the yield of heavier and the lighter fraction to the concentrate and tailing streams. The results are tabulated in Table-2 for different experimental conditions. Fig. 2 has been plotted using Cumulative time on X-axis of reject against Cumulative weight % of lighter fraction reporting to reject stream on the ordinate.
It is interesting to note that with prolonged collection of reject material up to 4 minutes with incremental time interval of 1 minute, the proportion of sand particles reporting to reject stream selectively increases simultaneously. However, a linear increase in the proportion of sandy particles to the reject stream is noticed for experiments carried out with water flowrate of 2.0 and 2.2 Lpm. Whereas, for the experiments carried out with higher water flowrate of 2.6 and 2.8 Lpm an exponential variation in the proportion of sand particles selectively reporting to reject stream is noticed.
Fig.3, illustrate the amount of heavier minerals reporting to the reject stream. From this figure it can be noted that up to 2 minutes of oscillation period no misplacement of heavies into the reject takes place and is independent water flow rate. Whereas, after two minutes of oscillation period the percentage of heavies to get last in the tailing stream is very large and becomes highly sensitive to the proportion water flow evidenced from the parabolic nature of the curves.
Fig.4, depicts the influence oscillation time on the total misplacement, which is nothing but the sum of heavies into reject and lights into the concentrate expressed in percentage. From the nature of the plots shown it is worthwhile to mention that, a complete reverse trend in the total mis-placement of material taking place is noticed when compared to the plots of shown in Fig.3. This is because, with prolonged oscillation time of the deck, although there is some loss of heavies into the reject (after 2 minutes of time) but complete rejection of sandy particles from heavies does not occur. This emphasis that for the production quality product we must keep the retention time for the particles more closer to 4 minutes with high water flow rates (at least 2.60 lpm), as noticed from the asymptotic nature of the curves obtained for 2.6 and 2.80 Lpm of water flow rates.
Conclusions:
From the discussions made above the following are the important conclusions that can be drawn for the beneficiation of Beach Sands
- An increased retention time of particles reduces the yield of concentrate containing heavy minerals almost linearly in which the rate of decrease is based upon the amount of flow rate of water on the deck
- The rate of removal of reject sand from heavy minerals is found to vary with respect to the water flow rate in the following manner:
a. A linear variation with 2.0 – 2.2 lpm
b. Exponential variation with 2.6 – 2.8 lpm - For the production quality product it is necessary to give the retention time for the particles more closer to 4 minutes with high water flow rates (at least 2.60 lpm)
However, the above conclusions are highly subjective and need further experiments to be carried out (by varying other variables like deck inclination, length of stroke etc.,) for the confirmation of the above conclusion.
The Mozley Laboratory Mineral Separator is capable of treating particles below 2mm size. It is basically a laboratory testing device operated in batch process. For establishing applicability of flowing film gravity concentration processes and fixing their operating parameters use of this separator is found be extremely important. It not only determines the feasibility of the process but also simulates an industrial unit at laboratory stage. For rapid testing of the amenability of ore minerals for their beneficiation using flowing film gravity concentration devices such as tables, spirals and richert cones etc, use of this unit is found be the most convenient.
A similar attempt has been made to determine the use of applicability of flowing film gravity separators for the for the separation of total heavy mineral form the beach sand collected. The tests carried out are mainly aimed at determining the retention time for the particles to obtain optimum performance. Therefore, a series of 16 tests were performed by varying water flow rate and the shaking lime at different levels, each varied at four levels of 2.0, 2.2, 2.6 and 2.8 Litres/min and 1, 2, 3 and 4 minutes respectively.
Testing
Separating Talc using Gravity
Talc is an industrial mineral that has a theoretical formula of Mg3Si4O10(OH)2; it has been used in many industries such as paper making, paint, plastic, food, pharmaceuticals, cosmetics, ceramics, etc. The characteristics of the talc mineral in this project was investigated using X-ray diffraction and it was found to contain a fair amount of magnesite and iron oxide as major gangue. Experiments were conducted based on the interest of how well gravity separation (Spiral concentrator and Knelson concentrator) methods could enhance the whiteness of this specific talc mineral.
https://www.mcgill.ca/engineering/files/engineering/sure-2012-minmat-ding.pdf
Theory & Equipment
Gravity Separation
Gravity separation is a type physical separation method that relies on the density difference of valuable mineral and gangue.
Spiral Concentrator
Wet spiral separation is the technique used in this project. It is based upon a combination of the solid particle density as well as the particle’s hydrodynamic properties.
Particles in spirals follow two simple rules of separation:
- Light and large particles are pushed into the outer radius region and flow down.
- Heavy and fine particles remain in the inner radius region and glow down
Knelson Concentrator
Knelson concentrator separate particles by gravitational force which is strengthened by centrifugal movement.
Mozley Laboratory Separator
The Mozley table is a flowing film device designed to treat small amount of sample and analyze its recovery.
Experiment Design
- Talc, as the valuable mineral, has specific gravity of approximately 2.5 while one of the major gangue, iron oxide, has specific gravity of about 5.2.
- The objective is to concentrate the light particles (Talc).
Results
Talc and Iron Oxide Grade
The objective of this project is to improve talc grade whilst reduce gangue material’s mainly by spiral concentrators.
Whiteness
Whiteness is one of the most important criteria to decide the grade of talc; it is evaluated by the brightness and yellow index.
Conclusion & Future Work
- Gravity separation is proven to be an useful experimental method to improve the whiteness of Talc magnesite containing magnetite.
- Future work is mainly about optimizing the best condition for gravity separation of Talc.
Main Objective
To refine customized indicator mineral and geochemical methodologies to explore for poorly exposed specialty metal deposits In the Canadian Cordillera.
Assess heavy mineral separation by Mozley C800 Laboratory Mineral Separator with an emphasis on recovering Nb-bearing (pyrochlore and columbite-[Fe]) and rare earth element (REE)-bearing (monazite and REE-fluorocarbonates) minerals.
Evaluate the advantages of automated methods (QEMSCAN) over hand picking for advanced mineralogical studies.
The results of this study will form the basis to optimize indicator mineral methodologies to explore for carbonatite-hosted specialty metal deposits world-wide.
Project Outline
Limited exploration budgets and deposit and commodity specific exploration necessitates a more focussed, customized approach.
Stage 1 (previous work) involved characterising the Aley carbonatite, stream-sediment sample collection, and orientation survey. This involved chemical analyses of the sediments and selection of an optimal size fraction for indicator mineral studies (Luck and Simandl 2014; Mackay and Simandl 2014).
Stage 2 (current study) involves evaluation of inexpensive and rapid methods to produce heavy-mineral concentrates for specialty metal-targeted exploration. An initial assessment of the Mozley C800 Laboratory Mineral Separator (referred to from here on as Mozley C800) is presented using synthetic standards (prepared for this purpose) and stream-sediments collected from the Aley carbonatite drainage area. Minerals with high densities and constituent Nb, Ta, and light rare earth elements (LREE; La, Ce, Pr, and Nd) were selected as potential indicator mineral candidates.
Stage 3 (proceeding concurrently with stage 2) will address customization of microscopic, SEM, QEMSCAN, and electron microprobe methods in advanced mineralogical studies.
Study Area, Local Geology, and Stream Sediment Sample Locations
The Aley Carbonatite (290 km north of Prince George, BC; inset map) outcrops over a 3-3.5 km diameter area. Measured+indicated resources are 286 million tonnes at 0.37% Nb2O5 (Taseko Mines Limited, 2013). The Aley Carbonatite intruded into platformal carbonate and siliciclastic rocks of the Kechika Formation, Skoki Formation and Road River Group. Twelve stream-sediment samples (locations denoted by red circles) were collected from the stream draining the Aley carbonatite. From Mackay et al. 2015; modified after Mäder (1986), Massey et al. (2005), McLeish (2013) and Mackay and Simandl (2014)
Stream Sediment Orientation Survey
Concentration of potential carbonatite pathfinder elements for each size fraction of stream-sediment samples from the Aley area. The 125-250μm size fraction was selected for stage 2 and 3 geochemical and indicator mineral studies based on the distribution of material in the different size fractions and elemental concentrations (Nb, Ta, and LREE; La, Ce, Pr, Nd). Time permitting, the 63-125μm and 250-500μm size fractions would also be worthwhile for testing. From Mackay et al. 2015; modified from Mackay and Simandl 2014.
Potential Indicator Minerals
Potential indicator minerals for carbonatite-hosted specialty metal desposits include pyrochlore (4.20-6.40 g/cm³), columbite-(Fe) (5.30-7.30 g/cm³), fersmite (4.69-4.79 g/cm³), monazite (4.80-5.50 g/cm³) and REE-fluorocarbonates such as bastnaesite (4.95-5.00 g/cm³) and synchysite (3.90-4.15 g/cm³). These minerals have similar or higher densities than magnetite (5.10-5.20 g/cm³) in the synthetic standards used for initial optimization of Mozley C800 operating conditions.
(Left) Mozley C800 heavy mineral concentrate (sample AL-13-16) containing apatite (Ap), pyrochlore (Pcl), columbite-(Fe) (Cmb), and magnetite (Mag). Lithic fragments (Lit), and grain aggregates (Agg) are also present. Pyrochlore is identified by its distinctive octahedral crystal habit . Optical identification can be difficult in highly weathered grains. A magnet can be used to separate magnetite from columbite-(Fe) and other non-magnetic minerals.
a ) Fresh ( unweathered ) euhedral, dark brown and b) subhedral, strongly weathered pyrochlore grains from stream sediments sampled directly over the deposit (sample AL-13-04). c) Subhedral, slightly weathered and d) strongly weathered pyrochlore grains from downstream (8.8km; sample AL-13-16) of the Aley carbonatite.
a) Euhedral columbite- (Fe) partially surrounded by apatite (polished grain mount in plane polarized light; ppl). b) The columbite-(Fe) grain shows irregular texture characteristic for the Aley carbonatite (back scatter electron ; B S E ). Composite grains containing two or more mineral phases are common. c) Euhedral pyrochlore grain (ppl). d) The pyrochlore is highly fractured and contains dolomite (Dol) and minor monazite ( M n z ) inclusions (BSE). The grain also has a minor weathered rim of Nb and Fe oxide material. e) An anhedral apatite grain (ppl image) f) with subhedral pyrochlore and hematite inclusions. The apatite has an alteration (weathered) rim of hematite (Hem), magnetite and minor chlorite (Cl) (BSE).
Processing Procedure
(Left) A sample being poured onto a Mozley C800. Water is supplied to the v-profile tray by the wash water pipe and the irrigation pipes. Arrows denote the direction of water flow. Duration of processing varied during operating condition optimization to suit deposit characteristics and sample size. Other operating parameters were kept constant for all samples. From Mackay et al. 2015.
(Below) Separated concentrate (high density), middlings (medium density), and tailings (low density). Concentrate narrows to where the middlings start. Separation of middlings from tailings is marked by a decrease in the spatial density of grains. From Mackay et al. 2015.
Optimization of Operating Conditions
Synthetic standards (75g) were used to test operating parameters. They were made predominantly of quartz with 0.33 to 10 wt. % each of magnetite, garnet, and fluorite. The excellent correlation ( R 2 = 0 . 98 ) between magnetite in synthetic standards and in Mozley C800 concentrates indicates consistent concentration. Magnetite concentration increased by 5.5 to 228.2 times. From Mackay et al. 2015
The proportion of concentrate for five identical sub-samples (~75g) of AL-13-16 decreased with increasing processing time. All other parameters were kept constant. The 15 minute time interval was selected for the remaining samples; this time is a compromise which ensures adequate concentration of heavy minerals, minimizing loss to tailings. From Mackay et al. 2015
Results and Discussion
(Above) Most stream-sediment samples (-75g) show 24.7-32.0% of material retained in concentrate, consistent with the natural sample used during optimization. Sample AL-13-09 (sampled upstream of the carbonatite) shows noticeably lower proportions of retained concentrate (3.8%). (Below) Mozley C800 concentrates show large average increases in the concentration of Nb (4.3 times), Ta (3.1 times), and LREE (3.1 times) relative to raw (unprocessed) samples. Samples are ordered by their geographic location from west to east (see map). The decreasing carbonatite signature with increasing distance downstream is preserved. From Mackay et al. 2015.
(Above) Excellent correlation, based on high coefficients of determination (R2), of (a) Nb (R2=0.94), (b) LREE (R2=0.80), Fe (R2=0.86) and moderate correlation of (c) Y (R2=0.77) in raw samples and Mozley C800 concentrates indicates consistent and effective concentration of pyrochlore, columbite-(Fe), magnetite, monazite, and REE-fluorcarbonates. The low coefficient of determination (d; R2=0.23) between Ta concentrations in raw samples and Mozley C800 concentrates is likely due to concentrations near the detection limit. From Mackay et al. 2015
Conclusions
Mozley C800 Laboratory Mineral Separator is a compact, simple instrument with operating conditions that can be optimized for drainage-, deposit-, or commodity-specific conditions.
Mozley C800 increased concentrations of Nb (average factor of 4.3), Ta (average factor of 3.1), and LREE (average factor of 3.1) from stream-sediment samples.
Pyrochlore, columbite-Fe, monazite and REE-bearing fluorocarbonates were consistently concentrated.
Based on chemical analyses, a predictable relationship between indicator mineral counts in raw stream-sediment samples and concentrates should be expected.
These findings justify stage 3 of this project which involves microscopic, SEM (QEMSCAN), and electron microprobe methodology to reduce or eliminate the need for handpicking indicator minerals.
http://www.empr.gov.bc.ca/Mining/Geoscience/PublicationsCatalogue/GeoFiles/Documents/GF2015-7.pdf
Mozley Table Operating Manual
Recommended Use
 | ‘V’Profile Tray with KnockThe Separator fitted with the ‘V’ profile tray and knock mechanism is recommended for making separations of samples with a particle size range between 2mm and 100 microns. Recommended maximum size for particles to be treated is 2mm.
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Flat TrayThe Separator fitted with the flat tray is recommended for making separations of samples with a particle size range finer than 100 microns. |  |
Changeover from ‘V’ profile tray to flat tray and vice-versa may be accomplished in the minimum amount of time without use of tools.
Principle Of Operation — ‘V’ Profile Tray
The Separator consists basically of a shallow ‘V’ profile stainless steel tray, inclined at a shallow angle to the horizontal in the longitudinal direction.
The tray is oscillated horizontally in a direction 90 degrees to the maximum slope by a crank driven via pulleys by an electric motor.
The tray is also free to move in the longitudinal direction. The oscillatory motion causes a roller attached to the underside of the tray to ride backwards and forwards over a specially designed cam. Buffers at the ‘upstream’ end of the tray are held in contact with the ‘anvil’ (a reinforced frame cross member) by a spring. The action of the tray and cam causes the buffers to move away from the anvil a short distance then to be returned sharply by the tension in the spring. This provides the tray with a sharp knock in the ‘upstream’ direction twice in every oscillatory cycle.
An even film of water is provided over the entire tray surface by irrigation pipes around the circumference. The water is able to discharge over the lower edge of the tray via a launder into a bucket.
Tray slope, water flowrate and oscillation speed may be varied to suit the sample being treated.
Separation of mineral particles is carried out after placing a wetted sample on the tray near the ‘upstream’ end. On starting the Separator the sample collects into a narrow band along the apex of the ‘V’. The mineral particles are kept in motion by the action of the Separator.
High density particles (usually the valuable minerals) sink to the tray surface and are ‘thrown’ towards the ‘upstream’ end of the tray by the ‘knock’ action. Low density particles (usually gangue or waste minerals) are carried down the tray by the flow of irrigation water to discharge via the launder.
By analysing the products collected via the launder over specific time intervals, and also the products remaining on the tray surface at the end of the test run a complete grade/recovery picture may be built up for the sample.
Results obtained with the ‘V’ profile tray & ‘knock’ are comparable with results obtained by commercial sand table installations when running at maximum efficiency.
Principle Of Operation – Flat Tray
The Separator consists basically of a flat stainless steel tray, inclined at a shallow angle to the horizontal in the longitudinal direction.
The tray is oscillated horizontally in a direction 90 degrees to the maximum slope, by a crank driven via pulleys by an electric motor.
An even film of water is provided over the entire tray surface by irrigation pipes around the circumference. The water is able to discharge over the lower edge of the tray via a launder into a bucket.
Tray slope, water flowrate, oscillation speed and amplitude may be varied to suit the sample being treated.
Separation of mineral particles is carried out after placing a sample, in aqueous slurry form, on the tray near the ‘upstream’ end. On starting the Separator the sample spreads out into a thin layer on the tray surface. The mineral particles are kept in motion by the action of the Separator.
High density particles (usually the valuable minerals) sink to the tray surface and are retained. Low density particles (usually gangue or waste minerals) are carried down the tray by the flow of irrigation water to discharge via the launder.
By analysing the products collected via the launder over specific time intervals, and also the products remaining on the tray surface at the end of the test run a complete grade/recovery picture may be built up for the sample.
Results obtained with the flat tray are comparable with results obtained by commercial slime table installations when running at maximum efficiency.
Removal Of Tray
- Stop separator with tray at furthest travel towards the left hand (access panel) side.
- Disconnect from electricity supply.
Undo the four ‘over centre’ clips and remove access panel. 
Remove PVC Irrigation water tube from copper stub. 
Disconnect the four tray holding springs from pins on underside of tray 
Disconnect ‘knock’ spring (‘V’ profile tray only). 
Lift tray clear. (With ‘V’ profile tray take care to pass lip under washwater pipe). 
Fitting ‘V’ Profile Tray
 | Place tray in position. Ensure lip passes under washwater pipe, and the four bearings pads locate on the four pins |
 | Push PVC irrigation water tube onto copper stub and ensure washwater pipe is positioned as shown. |
 | Attach the four tray holding springs to pins on underside of tray. |
 | Attach ‘knock’ spring to hook. |
| Replace access panel. | |
| Re-connect to electricity supply. |
Fitting Flat Tray
| Place tray in position after first turning washwater pipe aside. Ensure the four pins locate in the four holes beneath the tray. |  |
| Push PVC irrigation water tube onto the copper stub and ensure washwater pipe is located as shown. (The washwater pipe is only required with the ‘V’ profile tray). |  |
| Attach the four tray rettaining springs to the four pins on underside of tray. |  |
| Replace access panel. | |
| Re-connect to electricity supply. |
Initial Setting Up
 | Remove Packing Strip From RotameterUndo and remove brass nut and copper outlet pipe. |
| Pull out black plastic packing strip. | |
| Replace brass nut and copper outlet pipe. |
 | Fit Launder Outlet Tube Push 1″ PVC tube onto launder outlet
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| Arrange tube to discharge into bucket as illustrated. |
Procedure For Setting Up -‘V’ Profile Tray
- Carry out ‘Initial Setting up Procedure’ (page 7).
- Carry out ‘Levelling and Slope Adjustment’ (page 9).
- Set speed at 70 rpm. (page 10).
- Set amplitude at 2½ inches (page 11).
- Connect water supply. Any supply of clean water is suitable which will give a minimum flowrate of 3 litres/minute. Pressure should be greater than 5 psi. but must not exceed 100 psi.
The water inlet pipe is ½ inch diameter. A suitable rubber or plastic hose should be pushed onto this and secured with a worm drive clip. - Connect electricity supply. See machine rating plate to ensure correct supply connection.
The cable fitted to the Separator is colour coded as follows :
BROWN : LIVE
BLUE : NEUTRAL
GREEN/YELLOW : EARTH - Switch on.
The Separator should run smoothly with a sharp knock occurring at regular intervals. If it does not, check drive belt tension (page 14), and knock adjustment (page 12). - Turn on washwater and irrigation water valves. Set irrigation water valve to give flowrate of ½ litre/ minute on the rotameter. Allow to run for a few minutes to clear air from the system.
- Switch off Separator and turn off washwater. (The irrigation water is automatically turned off by a solenoid valve).
- It is important that the tray surface is thoroughly wetted before attempting a separation.
To ensure adequate wetting the tray surface should be rubbed down and degreased with 600 or 800 grade ‘wet & dry’ emery paper. This may be used in conjunction with a detergent. Alternatively a scouring powder may be used.
After rubbing down, the tray should be washed off thoroughly with clean water, after which a continuous film of water should cover the entire working surface.
If any breaks appear in the water film, greasy or shiny spots are indicated. These should be removed by further treatment with the emery paper or scouring powder, followed by washing with clean water. To avoid greasy patches, touching the tray surface with the hand should be avoided. - Ensure tray surface and launder are thoroughly clean before starting a separation.
Procedure For Setting Up-Flat Tray
- Carry out ‘Initial Setting up Procedure’ (page 7).
- Carry out ‘Levelling and Slope Adjustment’ (page 9).
- Set speed at 90 rpm. (page 10).
- Set amplitude at 3½ inches (page 11).
- Connect water supply. Any supply of clean water is suitable which will give a minimum flowrate of 3 litres/minute. Pressure should be greater than 5 psi. but must not exceed 100 psi.
The water inlet pipe is ½inch diameter. A suitable rubber or plastic hose should be pushed onto this and secured with a worm drive clip. - Connect electricity supply. See machine rating plate to ensure correct supply connection.
The cable fitted to the Separator is colour coded as follows :
BROWN : LIVE
BLUE : NEUTRAL
GREEN/YELLOW : EARTH - Switch on.
The Separator should run smoothly. If it does not, check drive belt tension (page 14). - Turn on irrigation water valve and adjust to give a flowrate of 2½ litres/minute on the rotameter. Allow to run for a few minutes to clear air from the system.
- Switch off Separator. (The irrigation water is automatically turned off by a solenoid valve).
- It is important that the tray surface is thoroughly wetted before attempting a separation.
To ensure adequate wetting the tray surface should be rubbed down and degreased with 600 or 800 grade ‘wet & dry’ emery paper. This may be used in conjunction with a detergent. Alternatively a scouring powder may be used.
After rubbing down, the tray should be washed off thoroughly with clean water, after which a continuous film of water should cover the entire working surface.
If any breaks appear in the water film, greasy or shiny spots are indicated. These should be removed by further treatment with the emery paper or scouring powder, followed by washing with clean water. To avoid greasy patches, touching the tray surface with the hand should be avoided. - Ensure tray surface and launder are thoroughly clean before starting a separation.
Levelling and Slope Adjustment
 | Adjust both levelling jacks until adjacent castors are just clear of the ground and spirit level ‘A’ indicates ‘level’. |
| Adjust slope adjustment jack until spirit level ‘B’ indicates ‘level’. |  |
 | Lock all jacks in position by screwing down locking rings. |
The Separator will now be set at a slope of 1¾ degrees.
This will be suitable for all separations carried out on the flat tray and most separations carried out on the ‘V’ profile tray.
For separation of coarse, high density minerals on the ‘V’ profile tray it may be found necessary to increase the slope above 1¾ degrees, this may be done as required whilst the separation is in progress.
It may be found advantageous to place a 2″ high block under the slope adjustment jack.
Speed Adjustment
- Disconnect from electricity supply.
- Undo the four ‘over centre’ clips and remove access panel.
- Remove crank pin (see page 11).
- Speed adjustment is made by manually moving the drive belt to the pair of pulleys giving the speed required.
- To Increase Speed
First move drive belt to next smaller drive shaft pulley whilst turning pulleys by hand.
Then use same technique to move belt to next larger motor shaft pulley. Repeat procedure until required speed is obtained. - To Decrease Speed
Move drive belt first to next smaller motor shaft pulley then to next larger drive shaft pulley.
Repeat procedure until required speed is obtained.
It is important that drive belt is always fitted to corresponding matched pairs of pulleys, as shown in illustration.
Amplitude Adjustment
- Stop Separator with tray at furthest travel towards left hand (access panel) side.
- Disconnect from electricity supply.
- Undo the four ‘over centre’ clips and remove access panel to reveal crank and motor assembly.
- Undo crank pin with 13mm spanner and remove.
- Position crank bush over hole corresponding to amplitude required (by manually sliding tray).
- Replace crank pin and tighten.
- Replace access panel.
- Re-connect to electricity supply.
Knock Adjustment -‘V’ Profile Tray
Weak Or Nonexistent Knock (assuming that spring is connected correctly — page 5). This indicates stiff tray bearings. To remedy proceed as follows :
| Disconnect Separator from electricity supply. |  |
| Remove tray (page 4), apply grease to bearing pins and anvil (page 15). | |
| Replace tray (page 5). | |
| Lay underneath Separator and, using screwdriver, loosen the four screws holding the two bearing pads on one side of the tray. | |
| Re-tighten the screws ensuring that the bearing pads are exactly parallel with the tray. | |
| Re-connect to electricity supply. |
The tray should now run freely to give a satisfying knock !
Irregular Knock
This indicates that the roller block is not centralised. To remedy proceed as follows :
| Disconnect Separator from electricity supply. |  |
| Undo ‘over centre’ clips and remove access panel. | |
| Move crank by hand until tray is exactly at centre stroke. | |
| Slacken roller block securing bolt (using 13mm spanner) and slide roller block sideways until it is exactly on centre line of cam spindle (page 15). | |
| N.B. Bolt may have to be at one end of its slot. | |
| Re-tighten bolt. | |
| Re-connect to electricity supply. | |
| If knock is still irregular, repeat procedure, trying slightly different positions for the roller block until a regular knock is obtained. |
N.B. Knock amplitude is set at ¼ inch during manufacture and should not be altered.
Profile Adjustment — Flat Tray
 | The flat tray is provided with two sets of profile adjusters. |
 | The tray surface should be checked for flatness using a ‘straight edge’. |
 | If the tray surface is convex or concave the profile adjusters should be used as illustrated to make the tray surface as flat as possible. |
Drive Belt Tension
Failure of the tray to move, or erratic movement when the separator is switched on indicates a slack or broken drive belt.
To remedy proceed as follows :
- Disconnect Separator from electricity supply.
- Undo the four ‘over centre’ clips and remove access panel.
- Check for belt tension as illustrated. Approximately ¼” , 6 mm, sideways play is correct.
- If the drive belt is broken or slack loosen the four motor mounting nuts with the 10mm spanner as illustrated.
- Fit new belt if necessary : GOODYEAR 20½” x ¼” wedge.
- Ensure that belt is fitted to corresponding matched pulleys (see page 10) to give required speed.
- Push motor to right until belt tension is correct.
- Tighten the four motor mounting nuts.
- Replace access panel.
- Re-connect to electricity supply.
Lubrication : Grease
Use any good quality grease at regular intervals
| CAM Remove (with 13mm spanner). Apply grease to spindle. |  |
| Tray Bearing Pins (4) Remove tray & apply grease to bearing surfaces. |  |
| Crank Pins (2) Remove (with 13mm spanner) & apply greasePillow Blocks (2) Nipples provided for snap-on grease gun. |  |
| Buffers/Anvil (2) Apply grease to bearing surfaces. |  |
N.B.: Motor & Gearbox are sealed units with sufficient lubricant for life
Lubrication : Oil
Use Any Good Quality 30W Oil At Regular Intervals
| Roller |  |
| Bogies (4) |  |
| Castors (4) |  |
| Jacks (3) |  |
Procedure For Carrying Out A Separation -‘V’ Profile Tray
| |
| 2. Inspect sample — ensure that the size range is coarser than approximately 100 microns, and finer than approximately 2mm. If significant quantities of fine particles are present, screen the sample at 100 microns, and treat the undersize material on the flat tray. If significant quantities of coarse particles are present, screen the sample at 2mm and treat only the undersize material. | |
| 3. Riffle out a 50g to 100g representative dry sample and place on the tray, as shown. |  |
| 4. Carefully wet the sample using the wash-bottle. |  |
| 5. Start the Separator (and simultaneously the stop-clock. If used). |  |
| 6. Observe the motion of the solids on the tray. All the material should become mobile and move into a band along the apex of the tray.If the material is not completely mobile, speed should be increased.If excessive stirring is taking place, speed should be reduced. |  |
| 7. Irrigation water should be kept to a minimum. ½ litre/minute or less is usually sufficient, except with coarse, high density material. Excess water will cause turbulence and loss of valuable mineral to tailings. | |
| 8. A small amount of concentrate wash water should be added to suit (via the fixed copper pipe). | |
| 9. High density (concentrate) mineral will move towards the upstream end of the tray under the influence of the knock. Tray slope should be adjusted so that the tip of the concentrate lies within 2 inches of the upper end of the tray. Coarse samples will require a steep angle (up to 3° ). Finer samples will require a shallow angle (down to ¾°). | |
| 10. Low density (tailings) mineral will discharge via the launder into the bucket(s), provided. | |
| 11. When the required separation has been achieved (normally after 2 to 3 minutes), stop the separator. |  |
| 12. For a complete ‘grade versus recovery’ evaluation the entire tailing stream should be collected (whilst the separation is in progress) in consecutive timed batches; in a series of buckets. For less exhaustive testwork the entire tailing stream is regarded as one sample and may be run to waste, if the weight and grade of feed is known. | |
| 13. After stopping the Separator the material remaining on the tray (medium and high density mineral particles) may be divided into one or more ‘middling’ bands and ‘concentrate’ as required. | |
| 14. The middling band(s) should first be washed from the tray, via the launder, with the washwater bottle into separate beakers. |  |
| NB. When washing products from the tray care should be taken to ensure that none is left behind, either on the tray surface or in the launder. | |
| 15. Finally the concentrate may be washed from the tray into a beaker. |  |
Procedure For Carrying Out A Separation – Flat Tray
| |
| 2. Inspect the sample — ensure that the size range is finer than approximately 100 microns. If significant quantities of coarse particles are present, screen the sample at 100 microns, and treat the oversize material on the ‘V’ profile tray. | |
| 3. Place 100 g to 200 g of sample in a beaker and mix thoroughly with approximately 300 ml. of water and a little dispersant such as sodium silicate. |  |
| 4. Pour the pulp slowly and carefully onto the separator tray, as shown, using the wash pipe or wash bottle to remove the last traces from the beaker. |  |
 | 5. Start the Separator (and simultaneously, the stop-clock, if used). |
| 6. Observe the motion of the solids on the tray. After an initial stir with water from the washwater pipe or bottle all the material should be in motion. If there are motionless patches tray speed and/or amplitude should be increased. ‘Cloudiness’ may indicate excessive stirring in which case speed and/or amplitude | |
 | 7. It is normal for the sample to divide into two streams (due to wave action). Both streams should be roughly equal in length and width. If they are not, tray flatness (page 13) and level (page 9 ) should be checked. |
| 8. During the separation, tailings (low density mineral particles) will discharge via the launder into the bucket(s) provided. | |
| 9. When the required separation has been achieved (normally after approximately 3 minutes), stop the separator. |  |
| 10. For a complete ‘grade versus recovery’ evaluation the entire tailing stream should be collected (whilst the separation is in progress) in consecutive timed batches; in a series of buckets.For less exhaustive testwork the entire tailing stream is regarded as one sample and may be run to waste if the weight and grade of feed is known. | |
| 11. After stopping the Separator the material remaining on the tray (medium and high density mineral particles) may be divided into one or more ‘middling’ bands and ‘concentrate’ as required. | |
| 12. The middling band(s) should first be washed from the tray, via the launder, with the washwater pipe or bottle into separate beakers. |  |
| 13. Finally the concentrate may be washed from the tray into a beaker. |  |
| NB. When washing products from the tray care should be taken to ensure that none is left behind, either on the tray surface or in the launder. | |
Interpretation Of Test
Interpretation of a test run will vary from sample to sample, and will depend on the amount of information required. The following procedure must be carried out if a full Grade versus Recovery evaluation is required :
Sample Preparation
Having carried out the separation (see pages 17 to 20) the next step is to remove excess water from the samples produced during the test. This may be done by filtering or by allowing them to stand until all solids have settled out, then decanting the clear water.
Very fine tailing from the flat tray may require a couple of days to settle out fully, after which a piece of ¼ inch tube should be used to siphon off the clear water without stirring up the solids.
To avoid this problem the feed sample may be assayed and weighed accurately beforehand. The tailings may then be run to waste, and their assay and weight calculated by difference.
Having removed excess water, the samples should be transferred to enamel or stainless steel trays, using a small amount of water from the wash bottle to ensure that all traces of solids are recovered from the buckets and beakers.
The samples should be dried in an oven at a temperature of approximately 150 degrees c. and cooled.
Sample Analysis
The dried samples should be weighed carefully on an analytical balance. If concentrate weights are very small (they may be less than ½g) weighing should be to two or three places of decimals.
The weighed samples should be assayed for the element or mineral of interest.
Data Analysis See pages 22 & 23
To obtain Grade versus Recovery information proceed as follows :
- Tabulate sample weights and assays as shown.
- Add weights together to obtain calculated feed weight.
- For each sample divide weight by feed weight and multiply by 100 to give ‘% Weight’.
- For each sample multiply ‘% Weight’ by ‘Assay %’ to give ‘Units’.
- Add units together to give calculated feed units.
- Divide feed units by 100 to give calculated feed assay.
- For each sample divide ‘Units’ by feed units and multiply by 100 to give ‘Mineral % Distribution’.
- Subtract ‘TAIL 1’ weight from 100 to give ‘Cumulative % weight’ (Concentrate) for ‘TAIL 1’ (i.e. % weight of material remaining on tray).
- Subtract TAIL 1′ + ‘TAIL 2 ‘ weights from 100 to give ‘Cumulative % weight’ (Concentrate) for ‘TAIL 2’.
- Subtract ‘TAIL 1’+’TAIL 2’+’TAIL 3’weights from 100 to give ‘Cumulative % weight’ (Concentrate) for’TAIL 3′.
- Carry on as above to give ‘Cumulative % weights’ (Concentrates) for all samples.
- Calculate ‘Cumulative % Recovery of Mineral’ from ‘Mineral % Distribution’ using exactly the same method.
- Calculate ‘Cumulative Units’ from ‘Units’ using the same method and tabulate (These figures are not shown in the tables on pages 22 & 23.
- For each sample divide ‘Cumulative Units’ by ‘Cumulative % weight’ to give ‘Grade’ (i.e. assay of material remaining on tray).
- Plot ‘Grade’ versus ‘Recovery’ as shown on pages 22 & 23.
For a less exhaustive study the dried samples may simply be inspected visually or microscopically in order to estimate mineral content.
| FAULT FINDING CHART
| ||
| FAULT | CAUSE | TO REMEDY REFER TO PAGE: |
| Erratic or non-movement or tray when switched on | Loose or broken drive belt | 14 |
| Incomplete film of water over tray surface | Greasy or shiny patches due to insufficient rubbing down | 8 |
| Weak or non-existant knock (‘V’ profile tray) | Stiff tray bearings, or Spring not connected, or Lack of lubrication | 12 5 & 12 12, 15 & 16 |
| Irregular knock (‘V’ profile tray) | Roller block off-centre | 12 |
| ‘Dead’ spots in sample (ie sample not completely mobile) | Speed too low (and/or amplitude too low — flat tray only) | 10 & 11 17, 18, 19 & 20 |
| Excessive agitation of sample (‘cloudiness’ — flat tray only) | Speed too high (and/or amplitude too high — flat tray only) | 10 & 11 17, 18, 19 & 20 |
| Concentrate thrown over upstream end of tray (‘V’ profile tray only) | Insufficient slope | 9, 17 & 18 |
| Tip of concentrate moves down tray (‘V’ profile tray only) | Slope too steep | 9, 17 & 18 |
| Water/sample runs off one side of tray (flat tray only) | Separator not level | 9 |
| Uneven sample streams (flat tray only) | Separator not level, or Tray surface not flat | 9 13, 19 & 20 |
Operation Manual for Item Code No.
The information presented herein is to the best of our knowledge true and accurate. However it is offered as a guide only and no warranty or guarantee express or implied is made regarding the capacity, performance or suitability of any product.
All our products are sold subject to our conditions of sale, a copy of which is available on request.
