Solvent Extraction Electrowinning VS Cementation: Copper Leaching
In the commercial dump leaching of copper, two methods have been generally accepted as a means for recovering copper from pregnant leach liquors. The oldest and most widely used technique is copper cementation with scrap iron. The newer technique involves solvent extraction and electrowinning. As part of a program to assure adequate domestic supplies of […]
Laboratory Scrubber
The Bureau of Mines has funded an extensive research program to develop improved scrubbers for coal mine applications. This work shows that scrubbers can offer a highly effective technique for dust control during many mining operations. In the most recent applications, these scrubbers are usually mounted on or in the mining machine, and minimum scrubber […]
Hydroxyoximes
The kinetics of solvent extraction with hydroxyoximes are complex, involving mass transfer with chemical reaction in a heterogeneous system. One is therefore faced with a wide spectrum of possible behaviour within certain well defined boundary conditions. The extraction rate could be diffusion-controlled under all conditions and would thus depend on the interfacial area, and concentration […]
Temporary Emergency Replacement Mill Liners
Shell liners wear very fast in very large diameter autogenous and semi-autogenous mills. In addition to shell liner wear, the ends of the mill are susceptible to very high rates of wear, generally confined to fairly narrow bands. Due to the sheer size of modern mills, extensive downtime is required to replace shell liners or […]
How to Size a Water Spray Systems
Determine what diameter piping is necessary to obtain sufficient water flow to spray nozzles used for dust suppression. A simplified, diagrammatic method of calculating the flow of water through a proposed system consisting of a supply line and two banks of spray nozzles is outlined. How it Works The pressure versus flowrate of the supply at […]
Hot Rolling Metals in Vacuum
Among the significant technological accomplishments of the third quarter of the 20th century was the wide application of vacuum-to-metal melting. Many of the more common metals, as well as superior alloys of steel, have benefited from vacuum degassing, and the production of reactive and refractory metals leans heavily on vacuum-melting techniques. Fabrication and other forming […]
Heap Leaching Time
All metallurgical reactions are dependent on time, temperature, atmosphere (reducing or oxidising) and particle size. Particle size has been discussed and atmosphere will be discussed later. Temperature in heap leaching is dependent on ambient conditions and rates of reaction are not greatly effected during most of the year. Freezing in a northern climate or high […]
Grinding Aids
The general use of chemical grinding aids involving several different mechanisms for increasing throughput in the wet grinding of ores has been discussed in a number of recent publications. It appears from industrial scale testing that the use of selective dispersants with certain prespecified operating conditions is an approach which can produce two important results: […]
Increase Plant Throughput by Mill Expansion
Shortly after start-up, it was apparent that it would be difficult to obtain the plant design throughput. The ore sample that had been used for grinding test work was found to be much softer than that of the orebody in depth. This had led the designers to design without a crushing stage and to designate […]
Flux Lime
All forms of “lime” are used in the steel plant. Calcium hydroxide is used for water treatment, acid neutralizing, and as a lubricant for wire drawing. All the other limes are used as fluxes in the sintering plant, blast furnace or steel producing furnaces. In the production of self flux or super-flux sinter, high calcium […]