Aerofall Mill Liner Design

According to the manufacturer, a distinctive feature of the Aerofall mill, as compared to the conventional mill, is the special feature of its wedge shape “deflector” liner design (Figures 2 and 3) which was claimed to provide “keying” action in the mill that produces an important part of the crushing and grinding action in the … Read more

Pyrometallurgy Chrome Recovery Plant Design

Chrome Recovery Plant Design: The purpose of the design phase of this project was to prepare the preliminary design of a pilot plant capable of: treating an average of at least one hundred pounds per hour of metallic scrap, and recovering a minimum of 65 percent of the contained chromium and other valuable metals (for example … Read more

Recover Chromium from Scrap Metal

Although world chromium resources are ample for the foreseeable future, political and economic events have raised doubts about the uninterrupted availability and reliability of chromium supply. Chromium is used extensively in the metallurgical industry and has no technically viable substitute for such critical applications as nickel-base superalloys required for aircraft gas turbine engines. The United … Read more

Zinc Electrowinning from Chloride Electrolyte

Chemical and electrochemical leaching processes using chloride solutions (FeCl3, HCl, CuCl2) and dry chlorination with Cl2 gas followed by leaching of the resultant chlorides are some of the methods considered for treating fine-grained Zn-Pb-Cu-Fe sulphide ores and concentrates. These processes eventually result in an impure zinc chloride liquor which, after purification using either solvent extraction … Read more

Uranium Precipitation by Hydrogen Peroxide

Uranyl peroxide precipitation offers two advantages over other precipitation methods, product purity and product handling. However, since it is a less well known process than ammonia, caustic or Mag-Ox precipitation, it is helpful to demonstrate the advantages of hydrogen peroxide by comparing its performance with the widely known and used ammonia precipitation process. First, product … Read more

Solvent Extraction of Cobalt SX

The United States produces essentially none of the cobalt and less than 10 pct of the primary nickel it consumes each year. However, it has been estimated that U.S. resources of cobalt and nickel are 842,000 and over 15 million short tons, respectively. Present yearly domestic consumption of cobalt is about 9,000 short tons, while … Read more

Scrap Silver Recovery

The Bureau of Mines undertook a study of recovery of precious metal values from surplus and obsolete electronic gear as a part of its continuing effort to achieve maximum use and conservation of natural resources. During the early phase of the study it was learned that some military aircraft contained significant quantities of silver as … Read more

SAG Semi-Autogenous Mill Steel Consumption

Does a SAG Mill reduce steel consumption? Do SAG mills cost less to operate compared to conventional rod or ball mill grinding circuits? Mining companies are always searching for new ways to cut costs. In order to be competitive and justify the tremendous capital costs of new projects, there has been a strong trend toward … Read more

Selective Flocculation and Flotation

The Bureau of Mines undertook a research program to insure an adequate supply of iron raw materials for future iron and steel making needs. A sample was obtained of oxidized taconite from the western Mesabi Range in Minnesota, and the metallurgical response of the taconite to beneficiation by a process that included selective flocculation-desliming-cationic flotation … Read more

Rod Mill Grinding

A detailed experimental study of breakage kinetics in a batch rod mill indicates that while the system is inherently nonlinear, the feed disappearance kinetics for the finer sizes and the coarser sizes at high holdups is well represented by first-order behavior. The set of breakage distribution functions was found to be normalizable and independent of … Read more