| 摘要 |
<p>Non-sulphide iron ores are treated with an acid substance the anion of which is a constituent of an acid having a dissociation constant not materially below 10-7, and subjected to froth flotation in the presence of a collector for such ores which contains oil-soluble petroleum sulphonates as its major active constituent. The acid substance may be sulphuric, sulphurous, or phosphoric acid, sodium or potassium bisulphate, sodium chlorosulphonate, or waste gases containing sulphur dioxide. The petroleum sulphonate may be the water-insoluble waste product, known as mahogany soap, obtained from the reaction of sulphuric acid and petroleum hydrocarbons, and it may be used either alone or dispersed in petroleum hydrocarbon, alcohols, coconut or other glyceride oil, or other oily solvent. The ore may be de-slimed, or only partially de-slimed, before conditioning, which latter is preferably effected at high density and the conditioned pulp then diluted to froth flotation density before flotation. Preferably the acid substance is added in the conditioner, but it may be used in the de-sliming, in the flotation circuit, or be added at various stages. Frothing agents such as pine oil, cresylic acid, and water-soluble reaction products of sulphuric acid with petroleum hydrocarbons, may be employed. After a rough flotation, the collector may be removed from the concentrate by treating it with a dispersing agent and the concentrate then subjected to a cleansing operation using a flotation reagent which floats out silica or siliceous gangue. Specifications 2359/09 and 19856/14, [both in Class 82 (ii)], are referred to.</p> |
