GB840293A - Process for recovering flotation reagent - Google Patents

Abstract

840,293. Washing granular materials. UNITED STATES BORAX & CHEMICAL CORPORATION. Aug. 7, 1958 [Sept. 27, 1957], No. 25335/58. Class 82(2) In a process for separating components of a particulate mixture by means of an alkylamine salt reagent which adheres preferentially to the surfaces of one component, the reagent is released from the separated coated component by adding thereto an aqueous alkaline solution or an alkali metal or alkaline earth metal hydroxide in solid form. As shown, sylvinite ore is scrubbed in saturated brine in apparatus 12 to release the clay constituent which is removed with most of the brine by screw 14. The ore is then introduced into conditioner 20 (a rotating drum type of mixer) where it is treated in saturated brine with alkylamine salt reagent supplemented, if desired, by oil, and the conditioned ore is transferred to riffled, sloping table 24 which is subjected to shaking. Concentrated potassium chloride is collected at 25, middlings at 26 and tailings at 27. The middlings are further refined in flotation battery 30 after addition of frothing agent e.g. isocarbinol, the float concentrate 32 from which being combined with the concentrate at 25 and the tailings from which being combined with the tailings at 27 and disposed of at 36. The combined concentrate at 34 is de-watered in drag 136 and fed to mixer 40 in which it is mixed with alkali metal or alkaline earth metal hydroxide supplied from container 44. After treatment with the alkali, the concentrate is rinsed with brine supplied via line 46 and the mixture then delivered to centrifuge 50 for further washing and de-watering. The concentrate emerging from centrifuge 50 is dried in dryer 52 and screened at 54. The fines 58 are dissolved in water in dissolver 60 and supplied to mixer 40 and centrifuge 50 for use as washing brine. Released reagent is carried as a suspension in brine from mixer 40 at 68 and from centrifuge 50 at 69 and is delivered for re-use to conditioner 20 via line 74. The released reagent is neutralized in conditioner 20 to a PH of 7À2-7À8 by addition of acid (e.g. hydrocholric, phosphoric, sulphuric acetic or citric acid) from container 76. In a modification (Fig. 2, not shown), the released reagent is thickened before re-use. The reagent may be the salt of a primary alkylamine having a straight C8-22 alkyl chain and may be fully saturated or partially unsaturated, e.g. it may be derived from tallow, soya or coconut oil fatty acids, and may be supplemented by kerosene, crude oil or diesel oil. Reference is also made to the separation of (1) feldspar from silica, (2) phosphate rock from silica, (3) vermiculite from silicate or silica, and (4) mica and silica from beryl ores.