Amax Incorporated

Other

Guy W Lussiez

Hugh F Reid

Leo W Beckstead

Eddie C Chou

Mahesh C Jha

Raul M Hoover

Jean-Paul Duterque

Thomas W Polkinghorn

Lauren B Ames

Hexagonal cadmium sulfide, a bright yellow pigment useful in high temperature processing, is produced by reacting cadmium sulfate solution with a solution of a soluble sulfide under pressure and at a temperature of about 250.degree. C.

Production of hexagonal cadmium sulfide pigment

A method is provided for conditioning nickel laterite pregnant leach liquor in preparation for the recovery of nickel therefrom in which pregnant leach liquor is mixed in a reaction vessel under atmospheric pressure with an amount of roasted high-magnesium nickeliferous silicate ore to form a pulp thereof, the amount of roasted ore being at least sufficient to lower the free acid content of pregnant liquor entering the thickener to a level corresponding to a pH ranging from about 1.8 to 3. The pregnant liquor is conditioned by stirring the pulp thereof at a temperature not exceeding 100.degree. C. for a time sufficient to lower the free acid content of the resulting conditioned pregnant liquor to the desired level and to effect substantial precipitation of iron as iron hydroxide and dissolved silica in the liquor. The treated pulp is then passed to a thickener to provide an underflow of residual roasted ore and an overflow of conditioned pregnant liquor is passed to metal recovery while withdrawing the residual roasted ore from the thickener, a portion of which is then recycled to the reaction vessel to which freshly roasted ore is also added.

Conditioning of laterite pressure leach liquor

A process wherein nickel in an aqueous stream is recovered as nickel sulfide by precipitation in an autoclave with pressurized hydrogen sulfide in the presence of a large quantity of recycled fine nickel sulfide seed material is improved when operated under continuous conditions by introducing into the autoclave a small, controlled quantity of supplemental seed material designed to maintain the seed surface area within required limits.

Granulometric control of nickel sulfide precipitate

A spelling game in which words are randomly selected from a storage device and spelled by one or more players. The words are subdivided according to difficulty. A first player selects a difficulty level and a word is randomly selected from the appropriate section of storage. The word is pronounced and defined by a second player. The first player then spells the word. Other players may then contest the spelling and spell the word. Points appropriate to the difficulty level are added to the score of players who correctly spell the word and are subtracted from the score of players who incorrectly spell the word. The process is repeated with each player having an opportunity to be the first speller.

Spelling game

In the high-pressure sulfuric acid leaching of nickeliferous oxide and silicate ore, there is a tendency for the formation of scale on autoclave surfaces. The scale comprises oxides and sulfates of metals selected from the group consisting of aluminum, iron, silicon and magnesium. The scale is chemically removed by flushing the autoclave following completion of a leaching regime with a sulfuric acid solution containing about 20 to 100 gpl H.sub.2 SO.sub.4 at a temperature of about 150.degree. C. to 250.degree. C. and a pressure ranging from about 54 psig to 562 psig for a time sufficient to effect substantial removal of the scale.

Chemical dissolution of scale formed during pressure leaching of

A method is disclosed of separating a suspension of fine tailings particles from a material of value in a liquid medium which comprises, adding a small but effective amount of fluocculant to said liquid medium while mixing said liquid medium and continuing said mixing to effect flocculation of said fine tailings particles, passing said liquid medium containing said flocculated particles to a rotating pelletizing drum and subjecting said medium to the rotational action of said drum to pelletize said flocculated tailings particles, thickening said pelletized tailings particles to provide an underflow of said pelletized tailings particles, and disposing said pelletized tailings particles.

Solid-liquid separation of laterite slurries

Process and means are provided for reducing the viscosity of a work hardened slurry of finely divided ore having a pulp density of at least 15% by weight of solids, the process comprising, gently mechanically agitating a mass of said work hardened slurry confined in a container whereby to cause relative movement between said mass and a contacting surface such that said mass is subjected to shear forces, the relative movement being at a linear velocity sufficient to provide shear forces in said agitated mass in contact with the surface effective for reducing the viscosity to a desired level more than 50% below the original viscosity, and continuing said agitation at substantially said linear velocity until the viscosity has been reduced to said desired level. A rotating drum or a container with a stirring device may be employed for carrying out the invention.

Fluidizing means for reducing viscosity of slurries

A method is provided for separating chromium from lateritic ore. The ore which generally also contains nickel and cobalt along with other metal values is leached with a strong sulfuric acid solution of about 10 to 30 normal concentration at an acid to ore ratio of at least 3:1 by weight. The leaching is carried out at a temperature of at least 100.degree. C ranging as high as about 300.degree. C at above atmospheric pressure. An oxidant, such as manganese dioxide, is preferably added to oxidize the chromium to the hexavalent state, the manganese dioxide, or its equivalent, being advantageous in improving the chromium yield at the lower end of the leaching temperature range.

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Golden, CO, United States of America

Guy W Lussiez