Table of Contents Le concassage constitue la premiere etape de la comminution. Son objectif n’est pas la liberation des mineraux, mais simplement la reduction de dimension afin de faciliter la manipulation ulterieure du minerai. II est normalement fait a sec en deux ou trois etapes. L’alimentation provient de la mine et a une dimension pouvant … Read more

Use of Bleaching Clays in Water Purification

Table of Contents Bleaching clays have been used extensively in the oil-refining industries for a number of years. Their use in water purification is relatively recent and less extensive. They are frequently classified as (1) those naturally active and (2) those active after artificial activation with acid. Fuller’s earths fall within the general group of … Read more

Ball Mill Grinding

Table of Contents Three “ores” were used in theBall Mill Grinding experiments. It is doubtful whether material more resistant to grinding can be found among the world’s ores. When flotation was newer and regarded as the panacea in ore treatment, the Tri-State operators were critized for not grinding the entire mill feed to flotation size … Read more

How to Remove Quartz & Impurities from Refractory Clays

Table of Contents Sandy flint and pyritic plastic clays from east-central Missouri can be beneficiated to good firing quality by ore dressing methods. Quartz and pyrite were the chief contaminants removed by the two gravity concentration methods used in the studies. Most iron-oxide minerals in these clays occur as finely-divided, low-gravity, hydrous material, often in … Read more

Fine Grain Lead Zinc Sulfides Flotation

Table of Contents This investigation has shown that lead and zinc sulfide minerals, in pulps containing particles all less than 9 microns in size, may be selectively recovered by froth flotation. All but one of the samples yielded lead concentrates-containing at least 57 percent Pb. Selective recovery of lead in the lead concentrate from extremely … Read more

Explosives Explosions and Flames

Table of Contents This circular summarizes the research and technologic activities and publications of the Federal Bureau of Mines Division of Explosives Technology during fiscal year 1959 (July 1, 1958-June 30, 1959). Part I briefly describes the programs that were active during the report period and presents a summary of some of the information not … Read more

Spectrograph Analysis of Tungsten

Table of Contents One of the main advantages of this method for estimating impurities in tungsten is that the analysis is performed on the metal. Ideally, samples and standards should be of the same particle size, between 200- and 300-mesh but satisfactory semiquantitative analyses can be made on particles as coarse as 30-mesh. Another advantage … Read more

How to Separate of Tantalum from Columbium

Table of Contents Results of this investigation demonstrate that high-purity columbium and tantalum compounds can be obtained by application of the solvent extraction separation system: Hydrofluoric acid-sulfuric acid-methyl isobutyl ketone. This system is unique in that it not only separates columbium from tantalum, but separates these two metals from other metallic impurities. The system is … Read more

How to Operate a Blast Furnace

Table of Contents The experimental blast furnace has attracted increasing interest during the past decade as a practical means for investigating a broad range of blast-furnace smelting problems. Under experimental-furnace conditions, information can be obtained with less expenditure of time and raw materials and, therefore, at lower cost than comparable information could be obtained under … Read more

Phosphorus Pentoxide Content Determination Method

Table of Contents The precipitate method described herein is advantageous because of its rapidity and relative simplicity. This method eliminates the standardization of reagents, second filtration, washing of precipitate, and dissolving of ammonium phosphomolybdate precipitate, all of which are required in the titration step of the usual alkalimetric method. The precipitate method does not approach … Read more