Tungsten Trioxide Extraction Method

Some countries attach great importance to the recovery and utilization of secondary resources of tungsten, tungsten especially in some major consuming countries such as the US, Germany and Japan. Germany Star can company's main business is international trade refractory metals, long-term acquisition of various tungsten scrap at low prices from around the globe, extraction and separation of tungsten trioxide in a variety of tungsten scrap production line.

Currently, the extraction of tungsten trioxide general process is: the formation of tungsten ore after leaching soluble tungstate, cleaning after acidification or evaporative crystallization of ammonium paratungstate (APT), calcined to generate secondary sodium tungstate tungsten trioxide; also The hydrochloric acid into tungstic acid, tungsten acid decomposition of tungsten trioxide; resin method or membrane electrolysis technology to prepare tungsten trioxide.

U.S. tungsten trioxide extraction process is: first with sodium hydroxide solution tungsten-containing waste cooking, generating sodium tungstate, sodium tungstate crystals crystallized; then sodium tungstate crystals are dissolved in the mother liquor loop, to regenerate sodium tungstate solution was evaporated to form the ammonium and sodium tungstate containing tungsten trioxide, silicon, arsenic and other metals mother liquor, the mother liquor can be recycled, avoiding the past the process releases large amounts of acid and other issues.

Calcination method: First, in the 600 ~ 650 ℃ to remove moisture, organic impurities and carbon, and tungsten disulfide high-temperature calcination makes oxidized tungsten trioxide reacts with ammonia generated sodium tungstate, remove iron, fluorine. Silicon, phosphorus and other insoluble matter.

Electrolysis: (1) mixing the molten salt and water removal (2) the electrode process (3) Pre-electrolysis (4) electrolysis (main parameters: temperature, cell voltage, current density, electrolysis time, etc.) (5) separated from the tungsten powder collect. Preparation of raw material of the present invention is a low cost, short process, simple equipment, there is no solid, liquid and gas waste emissions, no secondary pollution, at low cost direct electrolysis of tungsten powder prepared from tungstate.
 

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