Extraction of Molybdenum Disulphide

Molybdenite is separated by crushing and liquid flotation from the felspar and quartzite which constitute the bulk of the ore. The molybdenite is finely dispersed in the ore, and most of it is ciosely associated with quartz in very fine 

By-product processing is also largely by crushing and flotation, but the flotation processes are more specialised because of the variety of ores involved and the need to separate the small molybdenum content from the major proportion of copper or other primary metals. Because the product is mainly used in steelmaking, oxidation to molybdic oxide is acceptable, and an intermediate roasting may also be used. 

In the British specification DEF-2304 the assumption was made that abrasivity was directly linked to silica and a limit of 0.02% was placed on the silica 

Typical analyses of three commercial powders are shown in Table 2.3 . They differ mainly in that the fine grinding of the Superfine powder increased the acidity and ailowed it to pick up some oii and water contamination. The acid insoiubies include siliceous material, and these may possibly be abrasive, but there is no direct correlation between silica content and abrasiveness. The molybdic oxide, formed by oxidation of molybdenum disulphide, is less abrasive than most technical grades of the disulphide itself, as shown in Table 2.4 and it is only the 

The purpose of the study was to assess this material as a potential source for lubricant grade molybdenum disulphide, because of the steady increase in its use in lubricants. However, the total consumption for lubricant use represents less than 4% of the primary molybdenite production. It seems unlikely, therefore, that the demand will justify even the low quoted cost of upgrading the by-product material, except where the availability of the indigenous source is important. 

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