Assaying, Microscopy, Mineralogy & XRF/XRD

Assaying, Microscopy, Mineralogy & XRF/XRD 2017-04-04T06:57:57+00:00
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Understanding Process Mineralogy (26 replies)

Sugar Watkins
2 years ago
Sugar Watkins 2 years ago

Process mineralogy is a term that is used in a lot of contexts from process optimization to geometallurgy but its usefulness and application is often clouded by misconceptions that it is too hard or “our ore body is homogeneous and simple”. I feel this is a poorly understood and often ignored tool in the process metallurgist's arsenal!Process mineralogy is important for process innovation and improvements.

Obersturmbann
2 years ago
Obersturmbann 2 years ago

Knowing mineralogy is absolutely an advantage to control the process parameters and improve the process efficiency. And I agree that most of the time it is ignored.

John Koenig
2 years ago
John Koenig 2 years ago

In college we took two quarters of mineralogy, hand specimens and microscopic, from the geology department. I kind of passed it off as not very valuable then, but I've used it hundreds of times in practice the last 40 years. It has given insights on why processes did and didn't work that led to major improvements. Lab assays shed no light on most of these problems.

Geometallurgy, as it's now coming to be called, usually consists of two people working together, a mineralogist who knows a little metallurgy and a metallurgist who knows a little mineralogy. The results coming from this work can be awesome.

I'll give an example. In one operation certain ores would produce tailings that would not react to flocculent in the tailings thickener. We had a mineralogist look at samples of tailings that flocculated well and tailings that absolutely wouldn't flocculate. He found one trace mineral, stilpnomelane, which was present only in the non-flocculating tails. He knew that this mineral tends to release magnesium ions into water, which might be important. That's when the light went off for this metallurgist who knows a little about mineralogy. Stilpnomelane releases magnesium ions into the process water that wind up binding to the silica surfaces in the tailings, passivating them to the cationic flocculent. The problem was solved by getting to the mine geologist and working the presence and absence of stilpnomelane into the incoming ore blend to keep it's concentration at tolerable levels. After this, the problem went away. This was later applied to other operations where it also influenced cationic flotation of silica.

As I've often said, we all should have paid more attention in mineralogy class.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

Mineralogy helps to know the properties and equipment required to take advantage of property for separation. Inter locking play a major role in processing. Grain size also helps us in grinding methods used. Many don't understand this and land in problems. Example - Pelletization.

Before designing ore property is different from the day plant is operated. Mineralogy helps to understand this and change flow sheet design suitably.

Oberfuhrer
2 years ago
Oberfuhrer 2 years ago

Very good approachin industrial minerals it is obvious that mineralogy is the key in mineral processing and plant efficiency control. This may be done by a mineralogical approach which may be very simple. For example when dealing with refractory minerals such as andalusite a simple and quick heavy liquor measurement at lab gives you the opportunity to track andalusite all over the system.

But it is also possible to have, for a given deposit, a matrix which may give you the mineralogical composition of any flow just with chemical analysis...This is a very classical tool in industrial minerals for kaolin and many other such as marble.

When mining and processing for metals it is of course important to follow the mineral you are recovering all along the process.
But do we need a mineralogical study? The answer is yes if you want to know the degree of liberation of the mineral you want to recover. This may be done by a QuemScan type analysis from time to time and it is very useful.

In any case there is always a significant profit to make also a mineralogical balance associated to a chemical one.

Tony Verdeschi
2 years ago
Tony Verdeschi 2 years ago

I myself take an abstract approach to mining always have always well mining is held In a definite path with no exploratory methods to derivate off what is common norms. ..Well I do and come up with results that will blow your mind or minds. Like I just came across a new process to remove Terbrium out of a paramagnetic ore in the range of 3.5 % ...gold ran 1.2 %

Hauptsturm
2 years ago
Hauptsturm 2 years ago

Understanding the mineralogy is key to addressing the performance of the process.

Tony Verdeschi
2 years ago
Tony Verdeschi 2 years ago

A whole lot of companies do not understand the chemistry and leave 90 % of what they are looking for in the clays due to lack of experience in the metallic’s they can’t see ...such as the 35 micron range and digressed into the 7.0 micron range to 1.0 micron range...35 microns being the clays, 7.0 micron the size of a blood molecule, and last the but not least 1.0 micron as that of a chromosome. ...transcending into the natural Nano range consisting of hydroxylcollodallials and natural Nanos formed in nature.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

MINERALOGY: Just like we study genetics of plants, animals, human, we study Mineralogy. It is so important. It plays a major role in controlling economics of Industry and profits and to take correct decision for any changes and understand burning problems.

Example:
Pellet plant. Plant is designed initially for an ore sample given by Client. After testing flow sheet is designed. Erected and commissioned. But the day it is operated after 1 year of sampling, plant do not respond as per design.
PROBLEM; On investigation (Mineralogy) it was found that ore fed was too soft as compared to sample(Too hard). The whole design parameters fail to give required results. Today in INDIA many pellet industries are facing this problem. Loosing revenue in RUPEES IN CRORE.
Hence while giving sample, variation in mineralogy is to be told to the vendor for a suitable design. 

Bill Rico
2 years ago
Bill Rico 2 years ago

I have found understanding mineralogy a key component in identifying process approaches over the past 30 years. In the last 12 months as a consultant, it was a key to solving a base metals mineral processing problem which had been seen as insurmountable by the Board.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

How MINERALOGY PLAY KEY ROLE IN OPERATION:

MOISTURE: If moisture in ore changes from normal 3 to 5% to 6 to 8% the flow-ability changes. Screen stops screening. Chutes get choked. Dry grinding cost increases, Grinding will become difficult. Feed tonnage will reduce. Due to this particle size output will contain more fines. Loss in crores. Balance sheet profits will be less.
HARDNESS: If hardness of ore is designed for 6 and you get feed for 8 hardness after commissioning, what will happen?

Feed capacity will reduce by 50%.

Cost of production will be double.

Put grain size will change to more fines.

Quality will be poor.

Production loss in crores, and profits will be Zero. Will go in negative.
Similarly many more problems will be faced if we don’t know the MINERALOGY.

Sturmbann
2 years ago
Sturmbann 2 years ago

Process mineralogy is the first step to ascertain the technology to be adopted either for beneficiation or refining. Selection of unit operations depends on this so that the simplest process flow sheet can be developed.

Gruppen
2 years ago
Gruppen 2 years ago

I am glad that after so many years, someone brought process mineralogy on to the Table.

Starting from exploration to mining to mineral processing to process selection to plant optimisation-etc there is no other (essential) tool better than mineralogy and liberation studies.

Ace Levy
2 years ago
Ace Levy 2 years ago

I thought process mineralogy had been around forever - perhaps it has been forgotten in recent years when XRF and AAS, including On-Stream Analysis, have been developed to give inexpensive and rapid assay results. Assays, of course, don't reveal much of the picture, except that something is going wrong! Flotation operators in past times had a feel for the plant and the ore, and some could tell you the concentrate and tails grade just by looking at the froth. I remember the days when vanning plaques (!) and binocular microscopes were important tools for looking at process streams, revealing not only value losses, but also the types of misplaced particles. This worked well for hour-to-hour process control in variable and difficult ores.

Tony Verdeschi
2 years ago
Tony Verdeschi 2 years ago

Particle size and particle matrix is so important when it comes to mining ...it's not taught in the mining universities and the evolve met mentioned of chemistry in the application and process line is not stressed sufficient enough nor even addressed ...and this approach should be ...first we start with a particle of a human hair at 75 microns then that of cotton lent that can just barely be seen at 55 to 65 microns degrading into the microns that cannot be seen at 45 microns and at this point it is necessary to rely on a microcrocope so you may see the elements ( metallic...gold which are encrusted in the matrix of clay) at 35 microns , we then regress microns that are interlaced in hydroxy colloidal s at 25 microns a whole lot of precious metals exist in this phase in petroleum oils and then a particle of blood at 7.0 microns descending to last but not least 1.0 micron that of a chromosome. At this point Nanos are present from 1 x 10 minus 1 thru 1 x 10 minus 9th power...there is an abundance of natural healthy hydroxy particles and abundance of natural Nanoparticle s located in nature. Research is lacking in these fields but not for me.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

Yes it is TRUE.

We have a subject in College called as particle technology where we study this type of R&D. But in mineral processing many have neglected it. Today we find in tailing metals like lead, zinc, Silver, in huge quantities for the reason as said by you. R&D is hardly 1%. Still we follow old and conventional systems only. My feeling may be due to clash in Branches at top post. Who is holding the POWER? Mineral engineering and Engineers are being neglected not getting opportunity to explore 100%.We draining $ in millions for lack of proper knowledge in operating process industry. It is a fact. Not accepting the TRUTH is the biggest problem.
The day industry accepts the TRUTH problems are solved and made profitable.

Gruppen
2 years ago
Gruppen 2 years ago

I want to make a general statement. There is no "process mineralogy"; there is "mineralogy. Without good understanding of mineralogy no operation, starting from exploration to mining to process development, can neither start and or operate effectively and properly, It is the most powerful “diagnostic tool" in the hands of every one dealing with mineral industry.

Tony Verdeschi
2 years ago
Tony Verdeschi 2 years ago

I am glad someone is listening to me ...maybe when I finish my book you gentleman may be interested in its contents and also relive like me that value does exist in the 1 %....especially the natural hydroxy colloidal s and natural Nanos prevalent in the mineral field.

Unterstarm
2 years ago
Unterstarm 2 years ago

You guys are picking things apart. Keep in mind that the whole process, from exploration drilling, met drilling, sampling, testing, process development, design of plant, potential variations in operating characteristics, and overall process objectives must be included in the analysis. I had an early experience where rock was being tested for crushing. The samples were collected and the tests performed. The tests indicated that the crushing index was high and would require 2 large gyratory crushers to perform the crushing task. After the plant was built and mining started, it was realized that the crushers were oversized for the required duty.

WHAT WENT WRONG?

Samples for crushing testing were collected from more competent rock, i.e. the large pieces were more competent that the fines (that's why the large pieces were large and the small pieces small. Competent vs. incompetent material.

Why do I bring this up?

We need to understand the rock/ore/waste characteristics, the variations in those characteristics (both initially and over time) and be able to design and operate with all of those characteristics and limitations in mind.

Ace Levy
2 years ago
Ace Levy 2 years ago

A complete view is required from start to finish, with whatever the appropriate tools are at each stage from exploration to product quality. As many others have found, representability of samples, or at least an understanding of how representative the samples are, is essential at each stage. The test procedure also needs careful examination with respect to the rock types being tested.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

In INDIA we have ISI standards for collecting samples. Major economics of process industry depends on this.

Helena Russell
2 years ago
Helena Russell 2 years ago

Go "Green" with non-nuclear density measurementshttp://www.itoms.com/products/gamma-densitometer-alternative/

Tony Verdeschi
2 years ago
Tony Verdeschi 2 years ago

You can over grind anything but with proper in lab research you solve your problems before they evolve.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

What you said is right. We have used Nuclear Density Gauges to measure DENSITY of slurry. They are good and working for the past 10 years.

Standartenfurer
2 years ago
Standartenfurer 2 years ago

Perhaps there are 5 misconceptions but there are also many perceptions that are correct.

Marshal Dienes
2 years ago
Marshal Dienes 2 years ago

Chemistry CREATES the world. Chemical engineering is the BACK BONE. All technologies are born from Chemistry and Chemical Engineering. Mineral processing is a small subject in Chemical engineering in UNIT OPERATIONS. For research purpose scientist study subject called PARTICLE TECHNOLOGY. Where all subjects of mineral processing is covered and go beyond to keep DAMS in safe condition, waste management, Leaching etc. All technology of chemical engineering is used to study behaviour of a particle under motion and stationary condition.

The subject technical auditing includes all such engineering knowledge to understand the process problems. It is a base for other technologies to follow. Any industry profits are DRAINED because of malfunctioning of plant, without proper knowledge in Chemical Engineering.

Bill Fraser
2 years ago
Bill Fraser 2 years ago

Totally agree. I found most people in the minerals processing world do not value the fundamental research much. They would rather spend $ on inefficient and ineffective testing regimes instead of looking at the chemistry side. That is being said technologies with chemistry background found themselves they have no place in this industry.

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