Manganese-(III) species is generated and regenerated in a mixed aqueous acid solution containing manganese-(II) species by injecting ozone gas in the mixed aqueous acid solution such that ozone oxidizes at least some of the manganese-(II) species to the manganese-(III) species with at least 60% Mn(III) generation efficiency. The acids include sulfuric acid and an alkane sulfonic acid. The aqueous acid solution containing manganese-(III) and manganese-(II) species is used to etch polymer materials. The etch is a chrome-free etch method.

Manganese-(III) species is generated and regenerated in a mixed aqueous acid solution containing manganese-(II) species by injecting ozone gas in the mixed aqueous acid solution such that ozone oxidizes at least some of the manganese-(II) species to the manganese-(III) species with at least 60% Mn(III) generation efficiency. The acids include sulfuric acid and an alkane sulfonic acid. The aqueous acid solution containing manganese-(III) and manganese-(II) species is used to etch polymer materials. The etch is a chrome-free etch method.

A process and system is provided for recovery of one or more metal values using solution extraction techniques and for metal value recovery. In an exemplary embodiment, the solution extraction system comprises a first solution extraction circuit and a second solution extraction circuit. A first metal-bearing solution is provided to the first and second circuit, and a second metal-bearing solution is provided to the first circuit. The first circuit produces a first rich electrolyte solution, which can be forwarded to primary metal value recovery, and a low-grade raffinate, which is forwarded to secondary metal value recovery. The second circuit produces a second rich electrolyte solution, which is also forwarded to primary metal value recovery. The first and second solution extraction circuits have independent organic phases and each circuit can operate independently of the other circuit.

A process and system is provided for recovery of one or more metal values using solution extraction techniques and for metal value recovery. In an exemplary embodiment, the solution extraction system comprises a first solution extraction circuit and a second solution extraction circuit. A first metal-bearing solution is provided to the first and second circuit, and a second metal-bearing solution is provided to the first circuit. The first circuit produces a first rich electrolyte solution, which can be forwarded to primary metal value recovery, and a low-grade raffinate, which is forwarded to secondary metal value recovery. The second circuit produces a second rich electrolyte solution, which is also forwarded to primary metal value recovery. The first and second solution extraction circuits have independent organic phases and each circuit can operate independently of the other circuit.

The method includes two technological segments (i) a reduction segment and (ii) an oxidation segment that are interconnected by various support technological processes for the regeneration of solutions and gases and heat recuperation. The reduction segment includes an electrolysis that is performed from a solution of chloride salts of an energy carrier. During the electrolysis, these elements reduce to a lower oxidation state, solidify on the electrodes or precipitate to a solid state. The solid substance thus obtained is the energy carrier that can be stored outside of the electrolyser until a need for additional energy emerges. During the electrolysis, chlorine gas develops that is collected and dissolved in water. An HCl solution is regenerated, which is used in the oxidation segment. Oxygen is released in this process. The energy that has thus been stored in the oxidation potential of the energy carrier is released during a spontaneous chemical reaction between the energy carrier and the HCl solution in the oxidation segment. In this chemical reaction, the oxidation state of the chemical elements which constitute the energy carrier is increased to an oxidation state identical to that from before the beginning of the electrolysis. The reaction product hydrogen is formed that represents a high calorific fuel. This fuel can be immediately converted to heat or electrical energy, without a need for intermediate storage, by known methods. Only water enters the entire method, oxygen and hydrogen leave, while the cycle is closed/cyclic for the remaining substances.

A method for predicting an electrode short circuit based on a current includes acquiring a current value of a cathode of an anode-cathode pair; acquiring a plurality of current values during a set period of time; determining an increased value of the plurality of current values varying with time; determining whether the increased value is within a set current range; if yes, using a linear fitting method to fit the plurality of current values in time sequence to obtain a linear model; acquiring a slope and a determining coefficient of the linear model; determining whether the slope is within a set slope range; if yes, determining whether the determining coefficient is smaller than a set determining coefficient value; if no, determining that there is a short circuit danger in the electrodes of the anode-cathode pair, and in other cases, determining that there is no short circuit danger in the electrodes.

Manganese-(III) species is generated and regenerated in a mixed aqueous acid solution containing manganese-(II) species by injecting ozone gas in the mixed aqueous acid solution such that ozone oxidizes at least some of the manganese-(II) species to the manganese-(III) species with at least 60% Mn(III) generation efficiency. The acids include sulfuric acid and an alkane sulfonic acid. The aqueous acid solution containing manganese-(III) and manganese-(II) species is used to etch polymer materials. The etch is a chrome-free etch method.

Manganese-(III) species is generated and regenerated in a mixed aqueous acid solution containing manganese-(II) species by injecting ozone gas in the mixed aqueous acid solution such that ozone oxidizes at least some of the manganese-(II) species to the manganese-(III) species with at least 60% Mn(III) generation efficiency. The acids include sulfuric acid and an alkane sulfonic acid. The aqueous acid solution containing manganese-(III) and manganese-(II) species is used to etch polymer materials. The etch is a chrome-free etch method.

Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M.sub.xO.sub.y in which M is tungsten, molybdenum or vanadium; 4x1000; and 2.5y/x7.

Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M.sub.xO.sub.y in which M is tungsten, molybdenum or vanadium; 4x1000; and 2.5y/x7.