Environmental Projects, Inc.

Hazen Research, Inc.

Technology Management Advisors LLC

Cyprus Metallurgical Processes Corporation

Resource Technology Associates

Wayne C Hazen

Enzo L Coltrinari

Dale Lee Denham, Jr

Rudolph Pruszko

Paul B Queneau

Jerome P Downey

David R Baughman

Roland Schmidt

James E Reynolds

John E Litz

Duane N Goens

Ralph B Tacoma

David L Thompson

John S Wold

A process for the production of sodium carbonate monohydrate is disclosed. The process includes heating a feed stream containing trona and insoluble impurities in a calcining apparatus to a temperature of less than about 350&deg; C. to form anhydrous sodium carbonate. The anhydrous sodium carbonate is contacted with a saturated sodium carbonate brine solution to form sodium carbonate monohydrate crystals. Sodium carbonate monohydrate crystals are separated from insoluble impurities.

Process for the production of sodium carbonate

The present invention provides a process for producing crystals of a polymorphic compound in a first crystal structure by introduction of the compound in a second crystal structure into a saturated brine solution of the compound under conditions in which formation of the first crystal structure is favored and without evaporation or changes in temperature. As the second crystal structure dissolves, the brine becomes supersaturated resulting in relief of supersaturation by formation of crystals of the first crystal structure. The process includes controlling supersaturation and its relief to achieve growth of existing crystals of the first crystal structure rather than nucleation and formation of new crystals. The resulting crystals are separated from insoluble impurities on a size separation basis.

Recrystallization process

The present invention provides a process for producing sodium carbonate monohydrate crystals by introduction of anhydrous sodium carbonate into a saturated sodium carbonate brine solution under conditions in which sodium carbonate monohydrate formation is favored. As the anhydrous sodium carbonate dissolves, the brine becomes supersaturated resulting in relief of supersaturation by formation of sodium carbonate monohydrate crystals. The process includes controlling supersaturation and its relief to achieve growth of existing sodium carbonate monohydrate crystals rather than nucleation and formation of new sodium carbonate monohydrate crystals. The resulting crystals are separated from insoluble impurities on a size separation basis.

Sodium carbonate recrystallization

A copper alloy plumbing fixture containing interdispersed lead particles coated non-continuously on a water contact surface to resist the leaching of lead into potable water systems. The leach resistant fixture is prepared by immersing conventional copper alloys in a bismuth nitrate solution, selectively and non-continuously coating the lead dispersoid particles on the water contact surface with bismuth, tin or copper.

Apparatus and method for inhibiting the leaching of lead in water

Disclosed are a variety of processes for the purification of saline minerals and in particular, trona. Some of the processes include a combination wet and dry recovery process which results in high recovery and purification at relatively low cost. The dry separation methods can include density separation, magnetic separation and electrostatic separation. Other processes include a modified slush process for the purification of calcined trona (sodium carbonate) by the introduction of anhydrous sodium carbonate into a saturated brine solution and subsequent separation of insoluble impurities.

Method for purification and production of saline minerals from trona

Disclosed is a method for beneficiating trona from a feedstream containing trona and impurities by a dry separation method, namely, electrostatically separating a first portion of impurities from the trona at a temperature between about 25.degree. C. and about 45.degree. C. The disclosed beneficiation of trona method may also include separation of impurities from trona by other dry separation methods, such as density separation, magnetic separation and size separation, and/or by wet separation methods.

Method for beneficiation of trona

The present invention is a method to remove metals from solutions by precipitating the metals and adding cellulosic fiber to the solution. The precipitates attach to the cellulosic fibers to form products. The products may be removed from the solution by gravity separation techniques or by filtration. The removed products may be dewatered and incinerated. The method provides a simple and effective technique for removing low concentrations of metals from high volume solution streams.

Method for removing metals from waste solutions

A copper alloy plumbing fixture containing interdispersed lead particles coated noncontinuously on a water contact surface to resist the leaching of lead into potable water systems. The leach resistant fixture is prepared by immersing conventional copper alloys in a bismuth nitrate solution, selectively and noncontinuously coating the lead dispersoid particles on the water contact surface with bismuth. Tin may be substituted for bismuth to obtain similar results.

Method for removing metals from a solution

The invention comprises the treatment of metal oxides and mixed metal oxides and metal sulfides in a vertical tube reactor system having a downcomer section and a riser section in order to oxidize and dissolve the metal values in aqueous slurry primarily in the downcomer section and introducing a reducing agent comprising a formate species and reducing the dissolved metal values in the riser section. The reduced metal values are then separated with the gangue values from the product solution downstream from the vertical tube reactor system. The reduced metal values may then be separated from the gangue material by conventional solid separation techniques, such as flotation.

Method of recovering metals from ores using a formate reducing agent

Copper is recovered from copper salts selected from the group consisting of copper chlorides, copper oxides and copper oxychlorides by reducing the finely divided solid copper salts with hydrogen under turbulent conditions at a temperature greater than the melting point of elemental copper.

Growing community of inventors

Denver, CO, United States of America

Wayne C Hazen