970

Laboratory Extraction of Copper from Chalcocite by Roasting Reduction and Smelting

In a broad sense, sulfide copper pyrometallurgy is a batch sequence in three separate vessels, i.e., reverberatory furnace to yield “matte copper,” a converter to produce “blister copper,” and another reverberatory furnace to produce fire-refined copper. Matte smelting is relatively unchanged since it became universal practice some 50 to 60 years ago. It is now … Read more

Improving Crushing & Grinding Rates and Recovery Efficiency

The crushing section was designed to supply approximately 100 tons per hour of -5/8 in. material to the Fine Ore Bin. Early milling results indicated that the ore was somewhat harder than expected and the 7 ft. x 10 ft. Hardinge Rod Mill was proving to be a bottleneck. The comparatively wet ore, sizing up … Read more

Heap Leaching Oxide and Sulfide Copper Ores

Heap leaching is a simple means of recovering copper from oxide and oxide-sulfide ores. Although this method requires relatively low capital investment, it suffers from low copper recoveries and relatively high acid consumption. The objectives of this study were (1) to determine what factors influence these shortcomings, and (2) to establish a basis of correlation … Read more

Mathematical Modeling applied to Analysis and Control of Grinding Circuits Simulation of Closed-Circuit Grinding

The data acquisition and modeling efforts are described first, followed by discussion of some of the simulation results. Observations pertinent to steady-state operation are presented followed by a description of the application of a dynamic model of the grinding circuit for synthesis and evaluation of grinding-circuit control. Data Acquisition and Reduction Eleven streams are identified. … Read more

Grinding and Classification Control

The ore milled from start-up until January, 1968, was mainly massive sulphides, consisting of a complex mixture of iron, copper, zinc and minor amounts of lead sulphides with important associated values in gold, silver and cadmium (average specific gravity 3.8). Description of the Grinding-Classification Circuit  The crushing plant product (presently -14 mm) is stored in … Read more

Fine Dry Grinding of Iron Ore for Pelletizing

Screening during the production of high-grade lump ore for blast furnace burden, particularly from recently developed ore deposits in Australia, South America, and Africa, has resulted in large tonnages of fine iron ore. Certain owners have decided to stockpile these fines until some later date; however, others have either sold these fines “as is” for … Read more

Design of Flotation Cells and Circuits

After almost 60 years of application in this country froth flotation is still by far the most important process for concentrating metallic ores as well as a number of nonmetallic ores including fluorspar, phosphate rock, and potash. Its use on iron ores and coal is increasing. In the metals groups the largest plants and the … Read more

Tailing and Mill Process Water System Design Considerations

When the Henderson Project is completed in 1975, it will become one of the Free World’s largest primary molybdenum producers. The Henderson Mine will be located approximately 50 miles west of Denver, Colorado, on the eastern slope of the Continental Divide. Ore reserves are currently estimated to be 303,000,000 tons with a grade of 0.49% … Read more

Cyclone Separators for Solvent Extraction in Metallurgy

Solvent extraction as a method of purifying and concentrating metal values from solution has become a standard hydrometallurgical operation for recovery of both uranium and vanadium, and within the past two years it has been put into operation in a commercial plant for recovery of copper from leach solutions. In this first full scale solvent … Read more

Iron Ore Crushing & Grinding Controls

The Iron Ore Industry has perhaps seen more varied and drastic changes in its approach to crushing and grinding in the last 5 years than any of the other mineral industries. Multimillion ton per year plants have become common place. Centralized control and computers have become an established benefit. Autogenous grinding along with a variety … Read more