GB199051A - Improvements in and relating to the concentration of ores and minerals - Google Patents

Abstract

199,051. Marks, E. C. R., (Eureka Metallurgical Co.). Dec. 10, 1921. Treating ores to facilitate concentration.-In a process of concentrating ores, such as oxides, by flotation, the ore is coated with oil in a thick pulp having a low surface-tension value, and is then propelled to the surface of a liquid having a high surface-tension value, and the scum so formed is finally discharged into a water tank at a lower elevation, the product which settles at the bottom being recovered after the water has been drained off. The ore is crushed in a crusher 10 and passes through a screen 11 into a pulverizer 12, and then through a drag classifier 13 into a cone classifier 14. From the latter the separated slimes pass into a thickener 15 whilst the sands pass into a second pulverizer 16. The sands and slimes are then treated substantially alike, but separately The sands are coated with oil, preferably petroleum sludge, which is supplied from a vessel 19 and is introduced into the thick pulp of low surface-tension value in the mixer 17 in which it is thoroughly agitated, or an excess of oil may be added. Further to reduce its surface-tension substances, such as sodium sulphide, lye, nitre cake, sodium carbonate, common salt, small quantities of tension modifying oils or a soluble soap, may he added to the pulp from the vessels 18, 20, and 21, or its temperature may be raised by means of steam entering at 37. The excess water and oil is then recovered from the mixture by the cone 22, and may be used again, the thick pulp being discharged into four to five times its volume of cold water contained in a flotation cell 23. This water is clean and unmodified and its surfacetension comparatively high. Upon a slight agitation by the paddles 21, with or without the use of compressed air from 25, a scum appears on the surface of the pulp in the cell 23. This scum is delivered into water in a tank 26, at a lower elevation than the discharge from the flotation cell, so that the material is carried beneath the surface of the water and settles at the bottom from which it is removed after decanting the water. The slimes undergo a similar treatment to the sands, but more oil, water, and chemicals are required. They pass from the thickener 15 to a mixer 17<1> in which they are mixed with oils and chemicals from 18', 19<1>, 20<1> and 21'. The oily chemicallycontaminated water is recovered bv means of a filter press 22<1> and may be used again. The oiled slimes then pass to a flotation cell 23<1> having paddles 24<1> and an air supply 25<1>, from which they are finally discharged into a bin 26<1>. The oiled waters from the cone 22 and the filter press 22<1> are conveyed by suitable pipes and valves to storage tanks 28 and 31 respectively, and from these are conveyed back to either of the mixers 17, 17<1> for re-use.