Abstract: A magnetic separator having two rotating magnetic drums of opposite polarity which form between them a working air-gap, and having directionally magnetized block magnets on each side of both end-faces of the magnetic drums in a closed magnetic circuit, the magnets being connected together on one side of their poles, in pairs with unlike poles, by means of soft-iron parts, and being provided, on the other side, with pole shoes in which are mounted soft-iron parts designed as axes, the drums each being arranged in a housing comprising slide plates which are located in the working air-gap and which converge at the inlet and diverge at the outlet, the said drums comprising axial grooves distributed radially around their peripheries, or having peripheries of star-shaped cross section.

Abstract: Pyritic sulfur, organic sulfur and elemental sulfur are removed from coal by subjecting an aqueous slurry of coal to flotation for removal of most of the pyritic sulfur after which the coal obtained from the flotation is treated with dilute nitric acid which oxidizes any remaining pyritic sulfur and most of the organic sulfur, thus solubilizing the sulfur and reducing the sulfur content thereof. This coal can be filtered, washed and dried, if desired. Further reduction of organic sulfur is obtained by chemical treatment with unsaturated hydrocarbons which bind the organic sulfur thus lowering the sulfur content of the coal sufficiently so that the final product meets all requirements for use for power plants as well as for the metallurgical industry.

Abstract: A carnallite-containing crude salt is separated into a carnallite fraction, a sylvite fraction and an abandonable residue by grinding the salt to an average particle size of about 1.5 mm., conditioning the particles in a conventional manner with from 5-300 g/t of a conventional conditioning agent adjusting the relative humidity of the conditioned particles to 5-25%, and subjecting the resulting particles to electrostatic separation in two stages, wherein in the first stage the particles are subjected to a high voltage electric field having a field length of 0.4 to 1.2 m to separate a carnallite fraction by imparting to the carnallite fraction a high sidewards velocity relative to the initial downward velocity upon entering the field, thereby causing deflection of the carnallite away from a middlings fraction, and wherein in the second stage the first stage middling fracton is subjected to a second high voltage electric field having a field length of 1.5 to 2.

Abstract: A process for recovering copper-bearing mineral sulfides from a froth-floated, metallurgical concentrate by admixing the concentrate with a sufficient amount of N-mercaptoalkyl amide to depress the copper-bearing mineral sulfides during a flotation and recovering the non-floating copper-bearing mineral sulfides from the flotation process. In an embodiment, copper-bearing mineral sulfides are subjected to flotation process in the presence of a flotation agent with recovery of floated metallurgical concentrate containing copper-bearing mineral sulfides and thereafter refloating the metallurgical concentrate with admixing with N-mercaptoalkyl amide depressant to recover the non-floating copper-bearing mineral sulfides.

Abstract: The present invention is directed to silicon carbide whisker recovery from a mixture of silicon carbide whiskers and carbonaceous silicon carbide particles. The invention involves shredding the mixture down to a specified particle size, dispersing the mixture in water to form an aqueous mixture, agitating the aqueous mixture, adding surface active reagents to the aqueous mixture, agitating the resulting water-reagent mixture, subjecting the water-reagent mixture to froth flotation having at least three stages, removing tailings therefrom containing water and silicon carbide whiskers and removing float therefrom containing reagents and carbonaceous silicon carbide particles, performing a solid-liquid separation on the tailings and the float, thereby obtaining from the aqueous solution the desired silicon carbide whiskers and obtaining from the reagent solution a carbonaceous silicon carbide particle product.

Abstract: A combination of an ester of a mercapto carboxylic acid and an organic dithiol is a synergistic promoter for froth flotation of zinc sulfide ores.

Abstract: Magnetic separator apparatus is disclosed including means for establishing a magnetic field in a predetermined zone, a separating chamber provided with an inlet and an outlet for fluid, fluid-permeable and magnetisable packing material disposed within the separating chamber, a compensating element incorporating ferromagnetic material coupled to said separating chamber, and means for moving the separating chamber and the associated compensating element between a first position in which the separating chamber is within the predetermined zone and a second position in which the separating chamber is outside the predetermined zone. The magnetic field interacting with the compensating element generates balancing forces reducing the force required to move the separating chamber between its two aforesaid positions.

Abstract: Low molecular weight hydrolyzed polymers or copolymers of the general structure: ##STR1## exhibit excellent depressive action in the flotation of non-sulfide mineral ores thereby resulting in improved selectivity and recovery. The low molecular weight, partially hydrolyzed polymers or copolymers perform depressing action without resulting in any associated flocculation in the flotation system. The partially hydrolyzed polymers or copolymers can be combined with other known depressing agents for non-sulfide ores, such as starch, dextrin, gum and the like, to obtain equivalent or improved selectivity and recovery than would be obtained using these depressants alone.

Abstract: The solid organic materials contained in wet-process phosphoric acid are removed by froth flotation in a flotation cell in which the solid organic materials overflow with the foam from the top of the cell and the acid, after passing through the cell, is passed to extraction. The froth flotation process can also be used to remove defoamer and organic soluble materials from the wet-process phosphoric acid. Uranium in the partially purified phosphoric acid product is extracted with a suitable organic extractant, typically a mixture of mono- and di-(alkylphenyl) esters of orthophosphoric acid.

Abstract: A process for the improved beneficiation of phosphate ore in which the double float cationic (i.e., amine) floatation step is performed in two stages instead of the standard single stage, and which permits recovery of approximately two-thirds of the phosphate values that were previously lost in the amine tailings of the standard single stage process.

Abstract: A harvester for beans and like crop includes a pick-up reel having a width equal to the overall width of the harvester and leading to a first, cleaning, conveyor which terminates at an air passage incorporating a fan for generating a generally vertical air flow. Where the vertical air passage meets the cleaning conveyor, a rotary valve is provided which permits the passage of the beans and other parts of the crop but prevents or at least restricts the passage of the air flow into the space above the upper run of the conveyor.The rotary valve may take the form of a rotary vaned assembly having six vanes each of which is secured to one face of a hexagonal shaft and various forms of rotary valve are also described.

Abstract: An improvement is provided in a process for the flotation of an acid grade fluorspar enriched concentrate, having a sulfide sulfur content not greater than about 0.02%, from a fluorspar ore containing in addition to fluorspar substantial amounts of gangue minerals and metallic sulfide accessory minerals. The invention utilizes in this conventional flotation process an alkali metal sulfide, preferably sodium sulfide, as a depressor reagent, in substitution of environmentally objectionable sodium cyanide, to depress the flotation of metallic sulfide minerals, thereby rendering a flotation concentrate low in sulfide sulfur content while substantially reducing associated environmental effects.

Abstract: A phosphate ore flotation process subjecting a phosphate ore containing carbonate mineral impurities to froth flotation in the presence of phosphate depressants, said depressants are alkyl phosphonic acids, and a carbonate collector, said collector is fatty acids, removing the separated carbonate minerals from the overflow, and recovering the phosphate value in the underflow. The process of the present invention can be performed either prior to or after the separation of siliceous matter from phosphate minerals by methods known in the art.

Abstract: Pressure sorting method and apparatus in which the velocity of the rejected suspension component along the screen surface in a substantially direct path to a rejected suspension outlet has a vertical velocity component which is a multiple of the velocity of the accepted suspension through the screen openings by virtue of the cross-sectional area of the unsorted and rejects annular chamber at the inlet end being less than one third the sum of the clear cross-sections of the screen openings. The velocity ratio is maintained by decreasing the area of the annular chamber from the inlet to the rejects outlet. In a preferred embodiment, the accepts annular chamber increases towards the accepts outlet to compensate for the decrease in the unsorted and rejects annular chamber area.

Abstract: In the beneficiation of phosphate ore by flotation of siliceous material, the use of an alkyl-substituted phenyl ether amine or a hydroxyalkylated derivative thereof as a collector affords improved separation of phosphate from the siliceous matter.

Abstract: A process for producing a high grade molybdenum disulfide powder suitable for use in the formulation of chemicals and as an intermediate for synthesizing high purity molybdenum compounds by which an impure particulated molybdenite concentrate feed material is pulverized and thereafter is subjected to a plurality of purification treatments to effect a progressive extraction of the contaminating mineral constituents entrapped within the molybdenite particles. The purification treatments comprise a wash treatment of the molybdenite concentrate containing up to 10% by weight of hydrocarbon oil employing an aqueous solution forming a slurry which is subjected to successive steps of high shear agitation and low shear agitation to break up the agglomerated molybdenite particles and to effect a release of the mechanically entrapped very fine mineral particles which remain suspended in the aqueous liquid phase.

Abstract: A froth flotation method for the separation of trona from ground trona ore slurried in a saturated brine solution of sodium carbonate and sodium bicarbonate by using organic compounds of a specified type as flotation collectors.

Abstract: A process for beneficiating a finely ground ore containing sulfide minerals of copper and nickel by selective flotation to produce a copper concentrate and a copper-nickel concentrate comprises pulping the ore with water to form a slurry, conditioning the slurry with an aqueous solution of SO.sub.2 (H.sub.2 SO.sub.3) equivalent to from about 2 to about 4.5 pounds of SO.sub.2 per ton of dry ore for a time sufficiently long to maximize depression of the nickel minerals while maximizing activation of the copper minerals, wherein the conditioned slurry contains about 30 wt. % to about 35 wt. % solids, adding a collector and a frother to the conditioned slurry, subjecting the conditioned material to a rougher flotation stage to produce a rougher copper concentrate and a rougher tailings, conditioning the rougher tailings with additional collector and with Ca(OH).sub.

Abstract: An iron ore is finely ground and slurried prior to being subjected to treatment with a selective flocculant for iron values. Subsequent to treatment, the iron values are allowed to settle into the underflow concentrate and be recovered. The selective flocculant employed is a hydroxymethylated polyacrylamide having a high molecular weight and a degree of hydroxymethylation in excess of about 50%.

Abstract: A phosphate ore flotation process subjects a phosphate ore containing silica and silicates to froth flotation in the presence of a collector, said collector being a C.sub.54 high molecular weight tribasic acid comprising three carboxylic functional groups, recovering the phosphate concentrate from the overflow, and removing the separated silica and silicates in the underflow. The tribasic acids should be used in conjunction with fuel oil, not only to reduce the reagent consumption, but also to increase the grade and recovery of phosphate concentrate. The selectivity of this collector is so great that an acceptable phosphate rock concentrate can be obtained from the phosphate ore in a single anionic circuit.