The Dow Chemical Company

Saginaw Valley State University

Thomas A Vivian

Robert J Nankee

Kenneth O Groves

George W Eastland, Jr

Robert L Wright

Described is a method of separating and recovering metal values from a waste stream containing metal hydroxides comprising the steps of providing an aqueous waste stream containing metal values including chromium; subjecting the waste stream to an oxidation process to convert the chromium to chromium (VI); precipitating the other metal values in the aqueous stream by adjusting the pH of the stream to cause the precipitations; and separately recovering the chromium (VI) from the remaining metal values. The process described pertains to separating and recovering metal values such as those from an electroplating process or an electroless process wherein the metals may be iron, cobalt, zinc, cadmium, nickel, copper, silver, aluminum and chromium. The chromium recovery step is performed by oxidizing chromium (III) to chromium (VI) preferably in the presence of a manganese catalyst and preferably utilizing ultrasound waves. The remaining metal values are separated by the use of a chelating ion exchange resin.

Process of separating and recovering metal values from a waste stream

There is disclosed a composition of matter useful for stripping paint and varnish from substrates comprised of the conventional industrial chlorinated solvents, e.g. methylene chloride (dichloromethane) solvent and a wax, such as paraffin wax, which composition is improved by the addition thereto of a novel class of evaporation retarding chemicals resulting in a far more effective stripping action and a much improved environmentally desirable composition, with respect to the concentration of methylene chloride in the ambient atmosphere surrounding the work situs. The evaporation retarding chemical can be a surfactant, a resin plasticizer or ethylene or propylene carbonate.

Stripping compositions with reduced vapor containing MeCl.sub.2, a wax

A process for enhancing coal by removing the gangue (rock, shale, iron pyrites and the like) associated with the mined coal as it comes from the crushers before further treatment. The process described slurries the crushed run of the mine (ROM) coal with a heavy medium, such as perchloroethylene, for a short period of time at ambient or below temperatures, (i.e. slurry times of 5-30 minutes and temperatures of 90.degree. C. to below -10.degree. C.); thereafter allowing, in a substantially quiescent environment, the solids to settle or float as their inherent densities are greater or lesser respectively than the density of the heavy medium. After settling the float solids (mostly coal of lower sulfur and ash content) are separated from the heavy medium as one stream and the sink solids (mostly the gangue) as a second stream. These solids are each washed with hot (90.degree. C.-100.degree. C.) water and the vapor azeotrope which forms from the water and heavy medium mixture (azeotrope) removed. The now water wet solids are separated from the body of hot water and sent for further processing or loading. The solids, both the coal and the gangue, have a heavy medium content of less than about 400 parts heavy medium per million parts solids.

Coal enhancement process and equipment

A method of reclaiming clear PET resin from bottles and other containers is disclosed. PET resin contaminated with a hot melt type polyethylene copolymer based glue is treated with a chlorinated solvent and optionally subjected to azeotropic drying.

Recovery of polyethylene terephthalate (PET)

The in situ production of hydrochloric acid in a subterranean formation to increase the flow of gas or oil therefrom by decomposing a polyhalohydrocarbon in the formation is accomplished at lower temperature by injecting the polyhalohydrocarbon together with isopropyl alcohol or a Lewis acid, e.g. FeCl.sub.3, or a mixture of the alcohol and Lewis acid.

Acidification of subterranean formations employing halogenated

Compositions containing 80 to 99 percent by volume of chlorinated aliphatic hydrocarbons and 1 to 20 percent by volume of an alkylene glycol alkanoate or an alkylene glycol ether alkanoate have been found to be excellent for use in the vapor reflow of organic surfaces when the composition is employed in a superheated vaporous state.

Compositions for reflowing organic surfaces

Compositions containing 80 to 90 percent by volume of chlorinated aliphatic hydrocarbons and 1 to 20 percent by volume of an alkylene glycol alkanoate or an alkylene glycol ether alkanoate have been found to be excellent for use in the vapor reflow of organic surfaces.

Growing community of inventors

Midland, MI, United States of America

Thomas A Vivian