Lead is recovered from lead paste of a lead acid battery in a continuous and electrochemical lead recovery process. In especially preferred aspects, lead paste is processed to remove residual sulfates, and the so treated lead paste is subjected to a thermal treatment step that removes residual moisture and reduces lead dioxide to lead oxide. Advantageously, such pretreatment will avoid lead dioxide accumulation and electrolyte dilution.

Lead is recovered from lead paste of a lead acid battery in a continuous and electrochemical lead recovery process. In especially preferred aspects, lead paste is processed to remove residual sulfates, and the so treated lead paste is subjected to a thermal treatment step that removes residual moisture and reduces lead dioxide to lead oxide. Advantageously, such pretreatment will avoid lead dioxide accumulation and electrolyte dilution.

A method removes phosphorus from a phosphorus-containing substance. In the method, the phosphorus-containing substance that is used as a raw material for metal smelting or refining is reacted with a nitrogen-containing gas so that phosphorus in the phosphorus-containing substance is removed through nitriding. Prior to a treatment of a nitriding removal of phosphorus from the phosphorus-containing substance, a treatment is performed in which the phosphorus-containing substance is heated to an unmolten state temperature range so as to react with a reducing agent, thereby reducing at least a part of metal oxide in the phosphorus-containing substance.

A method removes phosphorus from a phosphorus-containing substance. In the method, the phosphorus-containing substance that is used as a raw material for metal smelting or refining is reacted with a nitrogen-containing gas so that phosphorus in the phosphorus-containing substance is removed through nitriding. Prior to a treatment of a nitriding removal of phosphorus from the phosphorus-containing substance, a treatment is performed in which the phosphorus-containing substance is heated to an unmolten state temperature range so as to react with a reducing agent, thereby reducing at least a part of metal oxide in the phosphorus-containing substance.

Lead is recovered from lead paste of a lead acid battery in a continuous and electrochemical lead recovery process. In especially preferred aspects, lead paste is processed to remove residual sulfates, and the so treated lead paste is subjected to a thermal treatment step that removes residual moisture and reduces lead dioxide to lead oxide. Advantageously, such pretreatment will avoid lead dioxide accumulation and electrolyte dilution.

Lead is recovered from lead paste of a lead acid battery in a continuous and electrochemical lead recovery process. In especially preferred aspects, lead paste is processed to remove residual sulfates, and the so treated lead paste is subjected to a thermal treatment step that removes residual moisture and reduces lead dioxide to lead oxide. Advantageously, such pretreatment will avoid lead dioxide accumulation and electrolyte dilution.

Proposed is a method for removing phosphorus from a phosphorus-containing substance which is applicable in an industrial scale so as to effectively reduce phosphorus contained in the phosphorus-containing substance. In this method, the phosphorus-containing substance used as a raw material for metal smelting or metal refining is reacted with a nitrogen-containing gas at a treatment temperature T (° C.) which is lower than a melting temperature (T.sub.m) of the substance, so that phosphorus is removed preferably in the form of phosphorus nitride (PN). In this regard, a nitrogen partial pressure and an oxygen partial pressure in the nitrogen-containing gas are preferably controlled, thereby reducing a load of dephosphorization process, for example.

Providing a method for selecting minerals containing arsenic. A peptide comprising an amino acids sequence according to the following formula: (T, S, N, or Q)-(H, P, or W)-(E, or D)-(H, P, W, R, or K)-(L, I, V, F, or A)-(L, I, V, F, or A)-(L, I, V, F, or A)-(T, S, N, or Q)-(H, P, or W)-(L, I, V, F, or A)-(T, S, N, or Q)-(L, I, V, F, or A) wherein one amino acid is respectively selected from each group defined by paired parentheses.

Providing a method for selecting minerals containing arsenic. A peptide comprising an amino acids sequence according to the following formula: (T, S, N, or Q)-(H, P, or W)-(E, or D)-(H, P, W, R, or K)-(L, I, V, F, or A)-(L, I, V, F, or A)-(L, I, V, F, or A)-(T, S, N, or Q)-(H, P, or W)-(L, I, V, F, or A)-(T, S, N, or Q)-(L, I, V, F, or A) wherein one amino acid is respectively selected from each group defined by paired parentheses.

Process for enhanced metal recovery from, for example, metal-containing feedstock using liquid and/or supercritical fluid carbon dioxide and a source of oxidation. The oxidation agent can be free of complexing agent. The metal-containing feedstock can be a mineral such as a refractory mineral. The mineral can be an ore with high sulfide content or an ore rich in carbonaceous material. Waste can also be used as the metal-containing feedstock. The metal-containing feedstock can be used which is not subjected to ultrafine grinding. Relatively low temperatures and pressures can be used. The metal-containing feedstock can be fed into the reactor at a temperature below the critical temperature of the carbon dioxide, and an exotherm from the oxidation reaction can provide the supercritical temperature. The oxidant can be added to the reactor at a rate to maintain isothermal conditions in the reactor. Minimal amounts of water can be used as an extractive medium.