Mobile Crushing Plants

The transportation of mine products incurs a cost which can have a significant bearing on the competitive position of the product. This statement not only holds true for the transportation of the finished product but certainly as much for the in-plant haulage of the raw materials. First of all, it should be differentiated between 3 categories … Read more

Miller Number – Slurry Rating Index

The development of a new means of measuring the relative abrasivity of a slurry came about by necessity in 1967 during a full scale loop test of a 560 H.P. reciprocating pump handling magnetite slurry. In order to evaluate the life of expendable fluid end parts, the question of the amount of attrition in a … Read more

How to Remove Mercury from Copper Concentrate

The copper-silver-mercury orebody of Gortdrum Mines (Ireland) Limited is located 3 miles north of the town of Tipperary in the Republic of Ireland. The first shipments of concentrates were made to the smelter in Europe in late 1967. In the spring of the following year, word was received from the smelter that these early shipments … Read more

Low-speed Gearless Converter Drive

The first motors of this type were built to drive ball mills in the cement industry, which are very similar to those employed for ore processing. Here, too, the tendency is to build units of ever increasing capacity. In the case of conventional drives with mechanical gearing, this involves correspondingly increasing difficulties. Technical principle A … Read more

Hydraulic Excavator

First, the hydraulic excavator enjoys tooth forces of the shovel because the dipper is attached to the machine with a dipperstick and boom, and can often actually realize greater tooth forces than a shovel because of the prize action of the dipper in hard digging. Digging range can be as deep as 35′ while dumping … Read more

Gypsum Calcining

Gypsum is the crystalline chemical compound CaSO4·2H2O. A close chemical relation – and frequently occurring with Gypsum – is Anhydrite which is CaSO4. Gypsun has wide commercial use because relatively simple heat processing reduces it to Plaster of Paris. While Anhydrite can be converted to Gypsum and thence to Plaster of Paris, the procedure is … Read more

Grinding and Concentration of Conglomerate Copper Ore

The conglomerate ore analyzed approximately 1.2% copper. The specific gravity of the ore was 2.72 and the bulk density was 108 pounds per cubic foot (determined on “as is” ore). The Bond laboratory ball mill work index was determined as 22.0 at 65 mesh. Autogenous Grinding Tests Crude ore was fed manually to the mill, … Read more

Simulation of Dry Ball Milling using Specific Power

The energy-size reduction relationship was the dominant form of mathematical model used in the description of tumbling mill grinding processes. Typically, in these models some single measure of product fineness (e.g. the 80% passing size, the size modules, the specific surface area) is chosen as the dependent variable and the energy input per unit mass … Read more

Continuous Particle Size Analyzer for Metallurgical Slurries

A continuous on-line particle size analysis system for solid/liquid suspensions is described. The basic sensor utilizes a centrifugal principle to separate particles according to size, the resultant separation being measured by means of beta-ray attenuation. Results obtained when analyzing a variety of materials at sizes from 65 mesh (210 microns) to 20 microns are discussed in … Read more

Adsorption Flotation Plagioclases

Sulfonate Collector Data on sulfonate adsorption by silicate minerals are very scarce in the literatures. The experiments were divided into two groups. The first group included the study of the flotation response of plagioclases as a function of pH and sulfonate concentration. This group also included the study of the effect of Ca(II) and Al (III) … Read more