US 6,402,807 B1 · Method for wet smelting of iron family metal bearing ores

Abstract

A smelting process wherein very pure iron or various iron family metals are economically obtained from ores which contain iron family metals by hydrometallurgy. The process involves: (a) grinding an ore containing iron family metals to pulverize the ore into fines of 25 mesh undersize; (b) immersing the pulverized ore into at least one inorganic acid having a concentration of 1N to 8N to elute the iron family metals into the inorganic acid to carry out a leaching; (c) filtering the resultant mixture of residue and inorganic acid containing eluted iron family metals to obtain a filtrate and a gangue; (d) adding an alkali to the filtrate obtained in step (c), whereby a hydroxide of the iron family metal is precipitated; (e) filtering the resultant suspension which contains the hydroxide to collect the hydroxide of iron family metals; and (f) heating the collected hydroxide or a dried hydroxide thereof in a reducing atmosphere at a temperature of 400 to 500° C. for 5 minutes or longer to carry out a pre-reduction and then immediately heating the resultant pre-reduced collected hydroxide at a temperature of 600 to 950° C. for 5 minutes or longer to carry out a reduction in the reducing atmosphere.

Claims21

Dependent claims

A method for wet smelting of iron family metal bearing ores comprising:

(a) grinding an ore containing iron family metals to pulverize the ore into fines of 25 mesh undersize;
(b) immersing the pulverized ore from step (a) into at least one inorganic acid having a concentration of 1N to 8N to elute the iron family metals into the inorganic acid to carry out a leaching and to provide a mixture of residue and inorganic acid containing eluted iron family metals;
(c) filtering the mixture of residue and inorganic acid containing eluted iron family metals from step (b) to obtain a filtrate and a gangue;
(d) adding an alkali to the filtrate obtained in step (c) to form a hydroxide of the iron family metals which is precipitated and forming a suspension which contains the hydroxide of the iron family metals;
(e) filtering the suspension which contains the hydroxide of the iron family metals from step (d) to collect the hydroxide of the iron family metals;
(f) rinsing the hydroxide of the iron family metals from step (e) with a sufficient amount of water to carry out the rinsing at a temperature of 40 to 60° C.;
and
(g) heating the rinsed hydroxide from step (f) or a dried hydroxide thereof in a reducing atmosphere at a temperature of 400 to 500° C. for 5 minutes or longer to carry out a pre-reduction to provide a pre-reduced collected hydroxide and then immediately heating the pre-reduced collected hydroxide at a temperature of 600 to 950° C. for 5 minutes or longer to carry out a reduction in the reducing atmosphere.

5 more elements

A method for wet smelting of iron family metal bearing ores comprising:

(a) grinding an ore containing iron family metals to pulverize the ore into fines of 25 mesh undersize;
(b) heating the pulverized ore from step (a) in the presence of one or more catalysts selected from the group consisting of an oxide, a hydroxide and a carbonate of an element selected from the group consisting of zinc, calcium, lead and potassium at a temperature of 600 to 1100° C. for 5 minutes or longer to carry out a reduction roasting;
(c) immersing the pulverized ore from step (b) into at least one inorganic acid having a concentration of 1N to 8N to elute the iron family metals into the inorganic acid to carry out a leaching and to provide a mixture of residue and inorganic acid containing eluted iron family metals;
(d) filtering the mixture of residue and inorganic acid containing eluted iron family metals from step (c) to obtain a filtrate and a gangue;
(e) adding an alkali to the filtrate obtained in step (d) to form a hydroxide of the iron family metals which is precipitated and forming a suspension which contains the hydroxide of the iron family metals;
(f) filtering the suspension which contains the hydroxide of the iron family metals from step (e) to collect the hydroxide of the iron family metals;
and
(g) heating the hydroxide from step (g) or a dried hydroxide thereof in a reducing atmosphere at a temperature of 400 to 500° C. for 5 minutes or longer to carry out a pre-reduction to provide a pre-reduced collected hydroxide and then immediately heating the pre-reduced collected hydroxide at a temperature of 600 to 950° C. for 5 minutes or longer to carry out a reduction in the reducing atmosphere.

5 more elements

Dependencies are inferred from the claim text.

Method for wet smelting of iron family metal bearing ores

Life of this patent

Method for wet smelting of iron family metal bearing ores

Life of this patent

Abstract

Claims21