Provided is a method for efficiently producing tungsten carbide from a raw material mixture comprising at least one valuable containing tungsten. The present invention relates to a method for producing tungsten carbide, comprising the steps of subjecting a raw material mixture comprising at least one valuable containing tungsten to electrolysis using an organic electrolytic solution to dissolve tungsten in the electrolytic solution; and calcining the electrolytic solution containing dissolved tungsten at a temperature of 800 C. or more to obtain tungsten carbide.

A system for recycling machined metal produced by an electrochemical material removal process. The system includes a machining unit and an electrowinning unit. The machining unit includes an anode to receive a workpiece, a cathode tool, and a first pulse generator to provide a voltage or current waveform between the anode and the cathode tool. The electrowinning unit includes an electrowinning cathode, an electrowinning anode, and a second pulse generator to provide a voltage or current waveform between the electrowinning anode and the electrowinning cathode. The machining unit is in fluid communication with the electrowinning unit.

A system for recycling machined metal produced by an electrochemical material removal process. The system includes a machining unit and an electrowinning unit. The machining unit includes an anode to receive a workpiece, a cathode tool, and a first pulse generator to provide a voltage or current waveform between the anode and the cathode tool. The electrowinning unit includes an electrowinning cathode, an electrowinning anode, and a second pulse generator to provide a voltage or current waveform between the electrowinning anode and the electrowinning cathode. The machining unit is in fluid communication with the electrowinning unit.

Methods and systems for producing are disclosed. A method for producing iron, for example, comprises: providing an iron-containing ore to a dissolution subsystem comprising a first electrochemical cell; wherein the first anolyte has a different composition than the first catholyte; dissolving at least a portion of the iron-containing ore using an acid to form an acidic iron-salt solution having dissolved first Fe.sup.3+ ions; providing at least a portion of the acidic iron-salt solution to the first cathodic chamber; first electrochemically reducing said first Fe.sup.3+ ions in the first catholyte to form Fe.sup.2+ ions; transferring the formed Fe.sup.2+ ions from the dissolution subsystem to an iron-plating subsystem having a second electrochemical cell; second electrochemically reducing a first portion of the transferred formed Fe.sup.2+ ions to Fe metal at a second cathode of the second electrochemical cell; and removing the Fe metal.

Methods and systems for producing are disclosed. A method for producing iron, for example, comprises: providing an iron-containing ore to a dissolution subsystem comprising a first electrochemical cell; wherein the first anolyte has a different composition than the first catholyte; dissolving at least a portion of the iron-containing ore using an acid to form an acidic iron-salt solution having dissolved first Fe.sup.3+ ions; providing at least a portion of the acidic iron-salt solution to the first cathodic chamber; first electrochemically reducing said first Fe.sup.3+ ions in the first catholyte to form Fe.sup.2+ ions; transferring the formed Fe.sup.2+ ions from the dissolution subsystem to an iron-plating subsystem having a second electrochemical cell; second electrochemically reducing a first portion of the transferred formed Fe.sup.2+ ions to Fe metal at a second cathode of the second electrochemical cell; and removing the Fe metal.

Methods and systems for producing iron from an iron-containing ore are disclosed. For example, a method for producing iron comprises: providing an iron-containing ore to a dissolution subsystem comprising a first electrochemical cell and a dissolution tank; dissolving the iron-containing ore to form an acidic iron-salt solution; reducing Fe.sup.3+ ions to form Fe.sup.2+ ions and electrochemically generating protons in the first electrochemical cell; circulating solution between the dissolution tank and the first electrochemical cell; transferring formed Fe.sup.2+ ions from the dissolution subsystem to an iron-plating subsystem having a second electrochemical cell; second electrochemically reducing a first portion of the transferred formed Fe.sup.2+ ions to Fe metal at a second cathode of the second electrochemical cell; and removing the Fe metal. The methods and systems optionally include removing one or more impurities found in the feedstock.

Methods and systems for producing iron from an iron-containing ore are disclosed. For example, a method for producing iron comprises: providing an iron-containing ore to a dissolution subsystem comprising a first electrochemical cell and a dissolution tank; dissolving the iron-containing ore to form an acidic iron-salt solution; reducing Fe.sup.3+ ions to form Fe.sup.2+ ions and electrochemically generating protons in the first electrochemical cell; circulating solution between the dissolution tank and the first electrochemical cell; transferring formed Fe.sup.2+ ions from the dissolution subsystem to an iron-plating subsystem having a second electrochemical cell; second electrochemically reducing a first portion of the transferred formed Fe.sup.2+ ions to Fe metal at a second cathode of the second electrochemical cell; and removing the Fe metal. The methods and systems optionally include removing one or more impurities found in the feedstock.

Methods and systems for dissolving an iron-containing ore are disclosed. For example, a method of processing and dissolving an iron-containing ore comprises: thermally reducing one or more non-magnetite iron oxide materials in the iron-containing ore to form magnetite in the presence of a reductant, thereby forming thermally-reduced ore; and dissolving at least a portion of the thermally-reduced ore using an acid to form an acidic iron-salt solution; wherein the acidic iron-salt solution comprises protons electrochemically generated in an electrochemical cell.

Methods and systems for dissolving an iron-containing ore are disclosed. For example, a method of processing and dissolving an iron-containing ore comprises: thermally reducing one or more non-magnetite iron oxide materials in the iron-containing ore to form magnetite in the presence of a reductant, thereby forming thermally-reduced ore; and dissolving at least a portion of the thermally-reduced ore using an acid to form an acidic iron-salt solution; wherein the acidic iron-salt solution comprises protons electrochemically generated in an electrochemical cell.

A method for separating an amount of osmium from a mixture containing the osmium and at least one other additional metal is provided. In particular, method for forming and trapping OsO.sub.4 to separate the osmium from a mixture containing the osmium and at least one other additional metal is provided.