Abstract:
Processes for the recovery of ruthenium from materials containing ruthenium or ruthenium oxides or from ruthenium-containing noble metal ore concentrates, with the steps of A. the introduction of the material into a highly alkaline alkali hydroxide melt in the presence of nitrate as oxidizing agent with the formation of an oxidized melt residue with water-soluble ruthenate (RuO4)2−, B. the dissolution of the oxidized melt residue obtained in water, C. the addition of a reducing agent, D. the precipitation of the metals formed, can also be used for separating off selenium. Optionally, ruthenium is separated off by distillation, instead of precipitation, following step B, with the steps of 5C the treatment of the ruthenate-containing solution with an oxidizing agent, 5D distilling off of the RuO4 obtained, 5E taking up of the RuO4 from step 5D in hydrochloric acid. By way of further subsequent purification steps, processes for the recovery of ruthenium targets are obtained.
Abstract:
The invention relates to the provision of noble metal-containing mixtures for a process for processing them by heating the mixture, preferably for processing them by means of an ashing process. This provision is characterized by the following measures: (a) moistening of the noble metal-containing mixture to be processed, (b) introduction of the moistened noble metal-containing mixture into at least one container which serves as diffusion barrier for water, and (c) introduction of the loaded container into a heat-resistant chamber together with at least one upper refractory mat. The noble metal-containing mixture is preferably moistened in the presence of a porous material and the chamber is closed by means of a heat-resistant covering. The invention further provides a processing process comprising the provision of noble metal-containing mixtures and also the heat-resistant chamber loaded with noble metal-containing mixtures itself. The process of the invention enables simple, clean recovery of noble metals in high yield from noble metal-containing mixtures.
Abstract:
For processing of noble metal-containing, moist recycling materials with an unknown noble metal content (hereinafter called “batch”), a moisture-binding agent is added for homogenisation and the batch is mixed with comminution of optionally pre-sent agglomerates to form a free-flowing and homogenous powder. Optionally, the following takes place subsequently for analysis: A at least one representative, volume-reduced sample is taken first of all, B the sample is dried, C the sample is optionally divided further and D the sample is analyzed and the noble metal content of the batch is calculated on the basis of the data a previously known or pre-calculated quantity of the moisture-binding agent being added before sampling (step A).
Abstract:
A recycling furnace is provided for processing potentially explosive precious metal-containing materials having organic fractions that combust with great energy. The furnace includes a switching facility for alternating operation of two burning-off chambers of the furnace between: (A) pyrolysis or carbonization under protective furnace gas in an atmosphere comprising maximally 6 wt-% oxygen, and (B) oxidative combustion of the organic fractions including carbon. The furnace has indirect heating and a control that determines the end of the pyrolysis or carbonization by a sensor and controls the switching facility to supply air or oxygen to the interior of the furnace. A continuous conveyor for dosing of liquids or liquefied substances during the pyrolysis is controlled by at least one parameter of post-combustion, preferably a temperature sensor. A single waste gas treatment facility is used for thermal post-combustion for the two furnace chambers.
Abstract:
In processes for removing ruthenium by distilling RuO4 from ruthenate-containing solutions with these steps of the treatment of the ruthenate-containing solution with an oxidising agent, distilling off of the RuO4 formed, absorbing the RuO4 from step II in hydrochloric acid, the oxidising agent is recycled into step I following step III. The processes can be carried out in reactor modules with A a reactor with a stirrer, gas inlet and gas outlet, B at least one scrubber connected in series downstream with the gas outlet via a line, C one or several gas absorbers connected in series downstream with the at least one scrubber via lines, E at least one line from the optionally last absorber for recycling into the gas inlet of the reactor or into a further module or into a facility for off-gas treatment.
Abstract:
In processes for removing ruthenium by distilling RuO4 from ruthenate-containing solutions with these steps of the treatment of the ruthenate-containing solution with an oxidising agent, distilling off of the RuO4 formed, absorbing the RuO4 from step II in hydrochloric acid, the oxidising agent is recycled into step I following step III. The processes can be carried out in reactor modules with A a reactor with a stirrer, gas inlet and gas outlet, B at least one scrubber connected in series downstream with the gas outlet via a line, C one or several gas absorbers connected in series downstream with the at least one scrubber via lines, E at least one line from the optionally last absorber for recycling into the gas inlet of the reactor or into a further module or into a facility for off-gas treatment.
Abstract:
For processing of noble metal-containing, moist recycling materials with an unknown noble metal content (hereinafter called “batch”), a moisture-binding agent is added for homogenisation and the batch is mixed with comminution of optionally pre-sent agglomerates to form a free-flowing and homogenous powder. Optionally, the following takes place subsequently for analysis: A at least one representative, volume-reduced sample is taken first of all, B the sample is dried, C the sample is optionally divided further and D the sample is analyzed and the noble metal content of the batch is calculated on the basis of the data a previously known or pre-calculated quantity of the moisture-binding agent being added before sampling (step A).
Abstract:
Ruthenium is separated from noble metal solutions, by: a) heating a noble metal solution containing ruthenium to a temperature of T=+50° C. to T=+65° C., the H+ concentration and Cl− concentration are greater than 1 mol/l each; b) addition of chlorate, the resulting suspension/solution having a temperature of T=+50° C. to T=+65° C., heating the suspension solution to T=+80° C. to T=+90° C. and passing a carrier gas through the suspension/solution and capturing the resultant ruthenium tetroxide; c) addition of bromate at a pH of 1 to 3, the resultant suspension/solution having a temperature T=+60° C. to T=+95° C., and passing a carrier gas through the suspension solution and capturing the resultant ruthenium tetroxide.
Abstract:
A method for dissolving noble metals out of segregated ores containing noble metals, comprising: reducing noble metal oxides present to the individual metals in finely divided form; oxidating the segregated ores and/or the noble metals with HCl and chlorate to yield a solution or suspension having a concentration of H+ ions of at least 1 mol/l, a concentration of Cl− ions of at least 1 mol/l and a temperature of at least 50° C.
Abstract:
A method is proposed for producing gold of high purity from noble metal solutions containing nitrate, with the following steps: a) Nitrate destruction in the noble metal solution, b) Addition of a gold ion reducing acid Fe2+ solution whose H+ ion concentration amounts to at least 4 mol/l, to the solution prepared in step a), whose H+ ion concentration amounts to at least 4 mol/l.