Nalco Chemical Company

Lawrence J Connelly

Robert P Mahoney

Robert L Wetegrove

William J Roe

E Michael Kerr

Ralph W Kaesler

David O Owen

Dodd W Fong

Peter E Reed

John R Hurlock

Edward G Ballweber

Radhakrishnan Selvarajan

James Kane

Krishnan J Pillai

David C Davis

Paul F Richardson

Robert C Sykes

Robert M Vallowe

E G Ballweber

David A Undlin

R James Shields

Steven J Abbatello

William K Gustafson

Ram-Aiyangar Venkatadri

The present invention related to the use of certain cross-linked diallyldimethyl ammonium chloride polymers in water-in-oil emulsion form for use as coagulants in suspensions of inorganic solids. The diallyldimethyl ammonium chloride polymers are preferably polymers of diallyldimethyl ammonium chloride, acrylamide, and triallylamine. The water-in-oil emulsions are formulated to invert after addition to the inorganic solids suspension, as the suspension travels to a mechanical thickening device for further processing. The inorganic solids from refuse or concentrate mineral processing applications may be coal, copper ore, sand, gravel, taconite, beryllium, trona, kaolin or precious metals.

Coagulant for mineral refuse slurries

A secondary polishing process for Bayer Process liquors suspension is described. The polishing process uses a combination of bio-polymers, particularly such bio-carbohydrates as dextran, with an inert insoluble solid, such as a filter aid, to treat the primary red mud settler overflow, then clarifying these treated overflow liquors in a secondary clarifier. Results provide for from 0-20 milligrams per liter suspended solids, often from 0-5 ppm suspended solids, and may make sand filter or Kelly filter operation an option in the Bayer Process.

Bayer liquor polishing

3-acrylamido-3-methylbutanoic acid copolymers of acrylamide or acrylic acid are selective flocculant for coal present in coal refuse slurries.

3-acrylamido-3-methylbutanoic acid copolymers as selective coal

A process for improved flocculation of Bayer process red mud-containing liquor uses a conventional water soluble anionic flocculant to form a red mud phase and a supernatant from the red mud-containing liquor, the supernatant containing suspended solids. The process is characterized by the addition of a water soluble clarification aid in addition to the conventional flocculant, wherein the clarification aid is pullulan, lactan, zooglan, rhamsan, or combinations thereof. The clarification aid is added to the red mud-containing liquor in an amount sufficient to reduce the concentration of suspended solids in the supernatant.

Clarification aid for the Bayer process

A digested slurry from a wet process phosphoric acid production process is dewatered by gravity-assisted vacuum filtration using as a filtration aid an aqueous solution of a polymeric filtraton aid that has been subjected to high shear mixing to enhance the performance of the filtration aid and enhance the filtration.

Method of dewatering a wet process phosphoric acid slurry

In the Bayer process for producing alumina from bauxite of the type wherein the bauxite is added to a caustic solution to produce a soluble aluminate solution and an insoluble red mud fraction which is then subjected to one or more separation steps to produce a thickener overflow which is then subjected to a Kelly Filter Press to polish the thickener overflow the improvement which comprises treating the thickener overflow and the filter aid with a filtration improving amount of dextran.

Use of dextran as a filtration aid for thickener overflow filtration in

A wet process production of phosphoric acid in which phosphate rock is digested, whereby phosphoric acid is released and calcium sulfate crystals are formed, employs a polymeric crystal modifier in the digestion stage of the process to improve the separation of the raw phosphoric acid product from the calcium sulfate crystals and to increase the concentration of phosphoric acid in the raw phosphoric acid product.

Crystal modification in wet process phosphoric acid production

A process for thickening gold ore slurries or slimes for gold purification which comprises adding to such gold ore slimes an effective amount of flocculant comprising a terpolymer containing 5-35 mole % 2-AMPS, 5-45 mole % sodium acrylate and 50-90 mole % acrylamide, said terpolymer having an RSV of at least 20.

Thickening of gold process slurries

The following inorganic compounds of iron, when added to Bayer process liquors, form a precipitate of the finely divided iron present in:

Iron removal from bayer process liquor

A process of flocculating suspended solids which comprises treating such suspension with an effective amount of a flocculant comprising a water-soluble terpolymer which contains sulfonate groups and has an RSV of at least 15.

Sulphonate-containing terpolymers as flocculants for suspended solids

A method for separating inorganic gangues from coal particulates dispersed in a coal refuse slurry comprises the selective flocculation of the coal refuse slurry by initially adding an anionic dispersant followed subsequently by adding an anionic flocculant, allowing the flocculating coal slurry obtained to settle and collecting a concentrated settled coal slurry having a lowered ash value. The dispersed inorganic gangues may be recovered by the addition of a cationic flocculant/coagulant with subsequent recycle of the aqueous phase.

Selective flocculation of coal

Acrylic acid copolymers and certain acrylic acid acrylamide terpolymers which contain amounts of 2-AMPS provide superior results when used to remove suspended red mud from aqueous solutions which contain alumina.

Flocculants for bauxite (red mud)

Poly N,N-dimethylaminomethyl acrylamide, when added to clarified trona solutions, improves the crystals subsequently formed from these solutions. Preferably, the poly N,N,-dimethylamino methyl acrylamide crystal modifier is used in conjunction with a water-soluble cationically charged coagulant.

Polymers for controlling soda ash crystal formation

Polyacrylamide dispersed in a polymeric latex may be hydrolyzed by the use of an alkali stable organic surfactant followed by the reaction of the polyacrylamide with an alkali metal hydroxide or quaternary ammonium hydroxide.

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Oak Lawn, IL, United States of America

Lawrence J Connelly