Rexnord Gmbh

Envirex Inc.

Der, Inc.

Pvl Limited Partnership I

United States Leather Holdings, Inc.

Paul R Erickson

Lloyd J Uhren

Charles Stark Applegate

Jeffrey M Waszgis

Lawrence M Sontoski

Albert R Sylvester

Richard G Waite

Kenneth A Pietila

A leather hydrolysate metal proteinate to be used as a metal nutrient for an animal feed. Chrome tanned leather scrap and shavings are heated in an aqueous solution with an alkali material to produce a water soluble, low molecular weight protein hydrolysate and insoluble chromium compounds which are subsequently separated from the hydrolysate. The hydrolysate is then oxidized to remove any objectionable trace organic residuals from the tanning process, and a di- or tri-valent water soluble metal salt is mixed with the hydrolysate to provide a metal proteinate. The metal proteinate, either as a liquid or a dried powder, can be used as animal or aquaculture diets.

Method of producing a metal nutrient for an animal feed

An improved method and apparatus for treating chromium containing leather scrap to recover chromium compounds and to produce a protein hydrolysate. The leather scrap is fed into an upstream mixing zone of a reaction vessel along with an alkali metal solution and the scrap and the solution are mixed by a plurality of kneading paddles carried by a rotating shaft. The mixture is then passed to a downstream hydrolyzing zone and conveyed through the hydrolyzing zone by a spiral flight. The mixture is heated by the injection of steam to thereby produce a hydrolyzed mixture comprising a protein hydrolysate containing suspended, insoluble particles of chromium compound. The hydrolysate is separated from the precipitated chromium compounds and can be recirculated to the reaction vessel while the chromium compounds can be recovered for use in the tanning process. The concentrated hydrolysate can be subjected to electrophoresis to increase the concentration of any desired amino acid in the hydrolysate.

Method and apparatus for treating chrome leather waste

An apparatus and process for the removal and recovery of sulfides from tannery waste water or liquor. The apparatus comprises a closed vessel, the sulfide-bearing liquor is introduced into a first or acidulation zone of the vessel and mixed with acid to decrease the pH, preferably to a value below 4.0, and generate hydrogen sulfide. The acidified liquor is then overflowed into a second or desorption zone of the vessel and slowly agitated and conveyed through the second zone by disc conveyors to release the hydrogen sulfide gas from the liquor. A slight vacuum is drawn on the vessel causing the released hydrogen sulfide gas to be drawn into a third reaction zone of the vessel, where the gas combines with sodium hydroxide solution to form sodium sulfhydrate. The effluent from the second zone can be filtered or dewatered and the filtrate discharged to a disposal site while the proteinaceous solids can be recovered for use as fertilizer. The sodium sulfhydrate produced in the third zone can be used in the unhairing operation of the tanning process.

Recovery of sulfides from tannery waste liquor

A method and system for dewatering coal fines from the centrate of a pipeline slurry centrifuge, to recover the coal and purify the water, includes blending the centrate from the centrifuge with slurry from the pipeline in the proportion of about 4:1. The blend is chemically conditioned agglomerating polymer, and then dewatered on a belt press. The cake from the belt press is dry enough to burn in the boiler, and the filtrate is clarified in a gravity clarifier. The clarifier effluent is clean enough for plant purposes or to return to the environment, and the clarifier underflow is returned to the blend for dewatering in the belt press. In a second embodiment, the blend is dewatered directly in a disphragm filter press without chemical conditioning, and the filtrate is clean enough to use directly without clarifying.

Method and system for recovering coal fines from pipe line coal slurry

A process for removing colloidal and soluble contaminants from impure water moving through a hollow, cylindrical microscreen under a positive head pressure, comprising dispersing insoluble, finely divided particulate matter into the impure water and rotating the microscreen at a rate that will form, during each rotation thereof, an intermixed layer of contaminants and particulate matter over substantially the entire inner surface of the microscreen through which the impure water is passing. The intermixed layer forms a filter substantially impermeable to contaminants and particulate matter of a size that could pass through the microscreen pores, but it is not impermeable to water. Preferably, the finely divided particulate matter can be a sorbent material, e.g. powdered activated carbon, so that contaminants are both filtered and sorbed from the water.

Water purification process

An alkaline wash water system for cleaning metal-working oil and scale from metal parts including a heated wash water recirculation system in which a small portion of the wash water is continuously removed, the oil and scale separated, and the cleaned portion returned with any make-up water required. The wash water is recirculated through a central zone of the separator. The separation may be a dual, alternate batch separation with a surge tank.

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Glendale, WI, United States of America

Paul R Erickson