US 2016/0102375 A1 · METHOD AND PLANT FOR PRODUCING IRON FROM ROASTED PYRITES

A method for obtaining/recovering metallic iron and/or iron compounds, more particularly iron chloride, from ores and/or ore residuals, preferably from pyrite residues, more preferably from roast pyrites obtained in the production of sulfuric acid, where the method comprises the following method steps:

(a) providing, more particularly processing, of a starting material in the form of at least one ore and/or ore residue, more particularly of at least one pyrite residue, preferably of one or more roasted pyrites obtained in the production of sulfuric acid, where the starting material comprises
i) iron, preferably as main constituent, and
ii) at least one noble metal, more particularly gold and/or silver, and also
iii) at least one further metal, preferably selected from the group of copper, zinc, lead, cobalt, titanium, manganese, vanadium and chromium;
(b) oxidation treatment, more particularly calcining and/or oxidative roasting, of the starting material provided in method step (a), preferably using at least one oxidizing agent, more particularly oxygen, to give iron oxide and oxides of the further metals;
(c) chlorination of the oxidation products, more particularly of iron oxide and oxides of the further metals, obtained in method step (b), using at least one chlorinating agent, comprising the chlorination of iron oxide and oxides of the further metals, to give iron chloride, more particularly iron(III) chloride, and chlorides of the further metals,
(d) selective removing and/or isolation of iron chloride, from the product mixture obtained in method step (c), and optional subsequent removing of chlorides of the further metals from the product mixture freed from iron chloride, where the selective removing and/or isolating of iron chloride, more particularly iron(III) chloride, takes place by sublimation of the iron chloride, more particularly iron(III) chloride, and the iron chloride, more particularly iron(III) chloride, removed selectively in the way is obtained as such by subsequent desublimation or the iron chloride, more particularly iron(III) chloride, removed selectively in this way is subjected to reduction to give metallix iron;
where the above-stated method steps (a) to (d) are carried out in the order listed above.

5 more elements

The method as claimed in any of the preceding claims, where in method step (d) the reduction of the removed and more particularly sublimed iron chloride, more particularly iron(III) chloride is carried out using at least one reducing agent, preferably hydrogen or natural gas.

The method as claimed in any of the preceding claims, where in method step (d) hydrogen chloride (HCl) results in the reduction of iron chloride, more particularly iron(III) chloride, in particular where the hydrogen chloride (HCl) is used in method step (c) for the recycling of the chlorinating agent, preferably ammonium chloride (NH4Cl), and/or in particular where the in particular gaseous ammonia (NH3) resulting from method step (c) in the chlorination, on the one hand, and the hydrogen chloride (HCl) resulting in method step (d), on the other hand, are combined and/or contacted and are brought to reaction to give the recycled chlorinating agent, preferably ammonium chloride (NH4Cl), preferably in a reaction and/or condensation device.

The method as claimed in any of the preceding claims, where the metallic iron obtained in method step (d) has a purity of at least 90 wt %, more particularly at least 95 wt %, preferably at least 98 wt %, more preferably at least 99 wt %, very preferably at least 99.5 wt %, especially preferably at least 99.99 wt %, calculated as element and based on the metallic iron obtained.

A method for obtaining/recovering metallic iron and/or iron compounds, more particularly iron chloride, from ores and/or ore residues, preferably from pyrite residues, more preferably from roasted pyrites obtained in the production of sulfuric acid, more particularly as defined in any of the preceding claims, where the method comprises the following method steps:

(a) providing, more particularly processing, of a starting material in the form of at least one ore and/or ore residue, more particularly of at least one pyrite residue, preferably of one or more roasted pyrites obtained in the production of sulfuric acid, where the starting material comprises
i) iron, preferably as main constituent, and
ii) at least one noble metal, more particularly gold and/or silver, and also
iii) at least one further metal, preferably selected from the group of copper, zinc, lead, cobalt, titanium, manganese, vanadium and chromium;
(b) oxidation treatment, more particularly calcining and/or oxidative roasting, of the starting material provided in method step (a), preferably using at least one oxidizing agent, more particularly oxygen, to give iron oxide and oxides of the further metals;
(c) chlorination of the oxidation products, more particularly of iron oxide and oxides of the further metals, using at least one chlorinating agent, more particularly a recyclable chlorinating agent, comprising the chlorination of iron oxide and oxides of the further metals, to give iron chloride, more particularly iron(III) chloride, and chlorides of the further metals,
where the chlorination is carried out using ammonium chloride as chlorinating agent,
where the chlorinating agent, more particularly ammonium chloride (NH4Cl), is recycled by recovery and/or removing of reaction products resulting from the chlorinating agent in the chlorination of the oxidation products, more particularly of preferably gaseous ammonia (NH3), and subsequent reaction of the reaction products, more particularly of preferably gaseous ammonia (NH3), with a preferably inorganic chlorine compound, more particularly hydrogen chloride (HCl), in particular where the preferably inorganic chlorine compound, more particularly hydrogen chloride (HCl), is obtained by the reduction, carried out optionally in method step (d), of iron chloride, especially using a reducing agent, preferably hydrogen or natural gas and
where the chlorinating agent obtained and/or recycled, more particularly ammonium chloride (NH4Cl), is used again in method step (c);
(d) selective removing of iron chloride from the product mixture obtained in method step (c), and optional subsequent removing of chlorides of the further metals from the product mixture freed from iron chloride, where the selective removing of iron chloride, more particularly iron(III) chloride, takes place by sublimation of the iron chloride, more particularly iron(III) chloride, and the iron chloride, more particularly iron(III) chloride, removed selectively in this way is obtained as such by subsequent desublimation or the iron chloride, more particularly iron(III) chloride, removed selectively in this way is subjected to reduction to give metallic iron;
where the above-stated method steps (a) to (d) are carried out in the order listed above.

8 more elements

The method as claimed in any of the preceding claims,

where the starting material comprises iron in the form of at least one iron oxide, in particular where the starting material comprises iron oxide in the form of iron(II) oxide (FeO), iron(III) oxide (Fe2O3) and/or iron(II, III) oxide (Fe3O4), and/or
where the starting material comprises iron in amounts in the range from 10 wt % to 75 wt %, more particularly in the range from 20 wt % to 70 wt %, preferably in the range from 30 wt % to 65 wt %, more preferably in the range from 40 wt % to 60 wt %, calculated as element and based on the dry weight of the starting material.

The method as claimed in any of the preceding claims,

where the starting material comprises the noble metal in amounts in the range from 0.1 g/t to 300 g/t, more particularly in the range from 0.5 g/t to 200 g/t, preferably in the range from 0.75 g/t to 100 g/t, more preferably in the range from 1 g/t to 50 g/t, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises gold in the form of metallic gold, and/or
where the starting material comprises gold in amounts in the range from 0.1 g/t to 15 g/t, more particularly in the range from 0.3 g/t to 10 g/t, preferably in the range from 0.5 g/t to 8 g/t, more preferably in the range from 1 g/t to 5 g/t, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises silver in the form of metallic silver and/or in the form of silver oxide, more particularly silver(I) oxide, and/or
where the starting material comprises silver in amounts in the range from 1 g/t to 300 g/t, more particularly in the range from 2 g/t to 200 g/t, preferably in the range from 3 g/t to 100 g/t, more preferably in the range from 5 g/t to 50 g/t, calculated as element and based on the dry weight of the starting material.

2 more elements

The method as claimed in any of the preceding claims,

where the starting material comprises the further metal in amounts in the range from 0.001 wt % to 10 wt %, more particularly in the range from 0.005 wt % to 5 wt %, preferably in the range from 0.0075 wt % to 3 wt %, more preferably in the range from 0.01 wt % to 2 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises copper in the form of copper oxide, more particular copper(I) oxide and/or copper(II) oxide, and/or where the starting material comprises copper in amounts in the range from 0.01 wt % to 5 wt %, more particularly in the range from 0.05 wt % to 3 wt %, preferably in the range from 0.075 wt % to 2 wt %, more preferably in the range from 0.1 wt % to 1 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises zinc in the form of zinc oxide, more particularly zinc(II) oxide, and/or
where the starting material comprises zinc in amounts in the range from 0.02 wt % to 10 wt %, more particularly in the range from 0.075 wt % to 5 wt %, preferably in the range from 0.1 wt % to 3 wt %, more preferably in the range from 0.2 wt % to 2 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises lead in the form of lead oxide, more particularly lead(II) oxide, and/or
where the starting material comprises lead in amounts in the range from 0.01 wt % to 5 wt %, more particularly in the range from 0.05 wt % to 4 wt %, preferably in the range from 0.1 wt % to 2 wt %, more preferably in the range from 0.15 wt % to 1.5 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises cobalt in the form of cobalt oxide, more particularly cobalt(II) oxide, and/or
where the starting material comprises cobalt in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises titanium in the form of titanium oxide, and/or
where the starting material comprises titanium in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises manganese in the form of manganese oxide, and/or
where the starting material comprises manganese in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises vanadium in the form of vanadium oxide, and/or
where the starting material comprises vanadium in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises chromium in the form of chromium oxide, and/or
where the starting material comprises chromium in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %, calculated as element and based on the dry weight of the starting material.

13 more elements

The method as claimed in any of the preceding claims,

where the starting material comprises at least one semimetal, in particular where the semimetal is selected from the group of silicon, arsenic, selenium, antimony, tellurium and combinations thereof, more particularly silicon, and/or in particular where the starting material comprises the semimetal in amounts in the range from 1 wt % to 40 wt %, more particularly in the range from 2 wt % to 30 wt %, preferably in the range from 3 wt % to 20 wt %, more preferably in the range from 4 wt % to 15 wt %, calculated as elements and based on the dry weight of the starting material, and/or
where the starting material comprises silicon, more particularly in the form of silicon oxide, preferably silicon dioxide (SiO2), and/or
where the starting material comprises silicon in amounts in the range from 0.5 wt % to 30 wt %, more particularly in the range from 1 wt % to 20 wt %, preferably in the range from 2 wt % to 15 wt %, more preferably in the range from 3 wt % to 10 wt %, calculated as element and based on the dry weight of the starting material, and/or
where the starting material comprises arsenic, more particularly in amounts of not more than 1 wt %, more particularly not more than 0.5 wt %, preferably not more than 0.3 wt %, calculated as element and based on the dry weight of the starting material.

1 more element

The method as claimed in any of the preceding claims,

where the starting material comprises at least one alkali metal and/or alkaline earth metal, more particularly at least one alkaline earth metal, preferably calcium,
in particular where the alkali metal and/or alkaline earth metal, more particularly the alkaline earth metal, preferably calcium, is present in the form of at least one salt, more particularly sulfate, and/or in particular where the starting material comprises calcium sulfate, and/or
in particular where the starting material comprises the alkali metal and/or alkaline earth metal, more particularly the alkaline earth metal, preferably calcium, in amounts in the range from 0.2 wt % to 20 wt %, more particularly in the range from 0.5 wt % to 15 wt %, preferably in the range from 1 wt % to 10 wt %, more preferably in the range from 2 wt % to 8 wt %, calculated as element and based on the dry weight of the starting material.

The method as claimed in any of the preceding claims,

where the starting material comprises at least one nonmetal, more particularly selected from the group of carbon, nitrogen, sulfur and phosphorus, more particularly sulfur, preferably in the form of the respective salts, and/or
where the starting material comprises sulfur, more particularly in the form of sulfur-containing salts, preferably sulfides, more preferably iron disulfide, and/or very preferably sulfates, in particular where the starting material comprises sulfur in amounts in the range from 0.2 wt % to 15 wt %, more particularly in the range from 0.5 wt % to 10 wt %, preferably in the range from 1 wt % to 8 wt %, more preferably in the range from 1.5 wt % to 6 wt %, calculated as element and based on the dry weight of the starting material.

The method as claimed in any of the preceding claims, where the starting material comprises the following ingredients, calculated in each case as element and based in each case on the dry weight of the starting material:

iron, more particularly in amounts in the range from 10 wt % to 75 wt %, more particularly in the range from 20 wt % to 70 wt %, preferably in the range from 30 wt % to 65 wt %, more preferable in the range from 40 wt % to 60 wt %;
gold, more particularly in amounts in the range from 0.1 g/t to 15 g/t, more particularly in the range from 0.2 g/t to 10 g/t, preferably in the range from 0.5 g/t to 8 g/t, more preferably in the range from 1 g/t to 5 g/t;
silver, more particularly in amounts in the range from 1 g/t to 300 g/t, more particularly in the range from 2 g/t to 200 g/t, preferably in the range from 3 g/t to 100 g/t, more preferably in the range from 5 g/t to 50 g/t;
copper, more particularly in amounts in the range from 0.01 wt % to 5 wt %, more particularly in the range from 0.05 wt % to 3 wt %, preferably in the range from 0.075 wt % to 2 wt %, more preferably in the rang from 0.1 wt % to 1 wt %;
zinc, more particularly in amounts in the range from 0.02 wt % to 20 wt %, more particularly in the range from 0.075 wt % to 5 wt %, preferably in the range from 0.1 wt % to 3 wt %, more preferably in the range from 0.2 wt % to 2 wt %;
lead, more particularly in amounts in the range from 0.01 wt % to 5 wt %, more particularly in the range from 0.05 wt % to 4 wt %, preferably in the range from 0.1 wt % to 2 wt %, more preferably in the range from 0.15 wt % to 1.5 wt %;
cobalt, more particularly in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %;
titanium, more particularly in the form of titanium oxide, for example in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %;
manganese, more particularly in the form of manganese oxide, for example in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %;
vanadium, more particularly in the form of vanadium oxide, for example in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %;
chromium, more particularly in the form of chromium oxide, for example in amounts in the range from 0.001 wt % to 2 wt %, more particularly in the range from 0.005 wt % to 1 wt %, preferably in the range from 0.0075 wt % to 0.5 wt %, more preferably in the range from 0.01 wt % to 0.1 wt %;
silicon, more particularly in amounts in the range from 0.5 wt % to 30 wt %, more particularly in the range from 1 wt % to 20 wt %, preferably in the range from 2 wt % to 15 wt %, more preferably in the range from 3 wt % to 10 wt %;
arsenic, more particularly in amounts of not more than 1 wt %, more particularly not more than 0.5 wt %, preferably not more than 0.3 wt %;
calcium, more particularly in amounts in the range from 0.2 wt % to 20 wt %, more particularly in the range from 0.5 wt % to 15 wt %, preferably in the range from 1 wt % to 10 wt %;
and/or
sulfur, more particularly in amounts in the range from 0.2 wt % to 15 wt %, more particularly in the range from 0.5 wt % to 10 wt %, preferably in the range from 1 wt % to 8 wt %, more preferably in the range from 1.5 wt % to 6 wt %.

13 more elements

The method as claimed in any of the preceding claims, where the starting material comprises the following ingredients, based in each case on the dry weight of the starting material:

iron(II, III) oxide (Fe3O4), more particularly in amounts in the range from 10 wt % to 80 wt %, more particularly in the range from 20 wt % to 70 wt %, preferably in the range from 30 wt % to 60 wt %;
iron(III) oxide (Fe2O3), more particularly in amounts in the range from 5 wt % to 50 wt %, more particularly in the range from 10 wt % to 40 wt %, preferably in the range from 15 wt % to 30 wt %;
silicon dioxide, more particularly in amounts in the range from 2 wt % to 30 wt %, more particularly in the range from 5 wt % to 25 wt %, preferably in the range from 10 wt % to 20 wt %;
and/or
calcium sulfate, more particularly in amounts in the range from 1 wt % to 25 wt %, more particularly in the range from 2 wt % to 20 wt %, preferably in the range from 5 wt % to 15 wt %.

2 more elements

The method as claimed in any of the preceding claims, where in method step (a) and/or before implementation of method step (b), the starting material is comminuted and/or homogenized, in particular where the starting material is adjusted to average particle sizes, more particularly an average particle size D50, in the range from 0.1 μm to 10 cm, more particularly 1 μm to 5 cm, preferably 100 μm to 1 cm, more preferably 500 μm to 0.5 cm.

The method as claimed in any of the preceding claims, where in method step (a) and/or before implementation of method step (b), the starting material is dried, in particular where the starting material is heated to temperatures in the range from 50° C. to 180° C., more particularly 80° C. to 160° C., preferably 100° C. to 140° C., and/or in particular where the starting material is adjusted to a residual moisture content of not more than 5 wt %, more particularly not more than 3 wt %, preferably not more than 2 wt %, more preferably not more than 1 wt %, based on the dried starting material.

The method as claimed in any of the preceding claims, where in method step (b) the oxidation treatment is carried out as a solid phase reaction and/or where the oxidation treatment is carried out with heating of the starting material and/or where the oxidation treatment is carried out at temperatures in the range from 500° C. to 1000° C., more particularly in the range from 600° C. to 900° C., preferably in the range from 650° C. to 950° C., and/or where the oxidation treatment is carried out using and/or in the presence of a preferably gaseous oxidizing agent, more particularly air and/or oxygen.

The method as claimed in any of the preceding claims, where the oxidation treatment is carried out in an oxidation and/or roasting device, in particular where the oxidation and/or roasting device is selected from the group of rotary kilns, drum kilns, fluidized bed kilns and entrained flow reactors.

The method as claimed in any of the preceding claims, where, in the oxidation treatment in method step (b), iron is converted at least substantially completely into the trivalent form, more particularly into iron(III), preferably into iron(III) oxide, and/or where, in the oxidation treatment in method step (b), iron(III) is obtained, and/or where, in the oxidation treatment in method step (b), iron(II, III) oxide and/or iron(II) oxide are converted into iron(III) oxide.

The method as claimed in any of the preceding claims, where the product mixture obtained in the oxidation treatment in method step (b) comprises iron(III) oxide in amounts in the range from 10 wt % to 95 wt %, more particularly in the range from 20 wt % to 90 wt %, preferably in the range from 40 wt % to 85 wt %, based on the dry weight of the product mixture obtained in method step (b).

The method as claimed in any of the preceding claims, where the product mixture obtained in the oxidation treatment in method step (b) comprises the further metal in the form of the metal oxide, preferably in the form of copper(II) oxide, zinc(II) oxide, lead(II) oxide and cobalt(II) oxide, and/or where the product mixture obtained in the oxidation treatment in method step (b) comprises silver oxide.

The method as claimed in any of the preceding claims, where in method step (c) the chlorination is carried out as solid phase reaction and/or where in method step (c) the oxidation products obtained in method step (b) and/or the product mixture obtained in the oxidation treatment in method step (b) is brought to temperatures in the range from 100° C. to 320° C., more particularly in the range from 150° C. to 302° C., preferably in the range from 180° C. to 300° C., and/or where in method step (c) the chlorination is carried out at temperatures in the range from 100° C. to 320° C., more particularly in the range from 150° C. to 302° C., preferably in the range from 180° C. to 300° C.

The method as claimed in any of the preceding claims, where the chlorination is carried out in a chlorinating device, more particularly where the chlorinating device is selected from the group of rotary kilns and drum kilns.

The method as claimed in any of the preceding claims, where in method step (c) iron oxide, more particularly iron(III) oxide, is reacted to give iron chloride, more particularly iron(III) chloride (FeCl3).

The method as claimed in any of the preceding claims,

where in method step (c) copper oxide, preferably copper(II) oxide, is reacted to give copper chloride, more particularly copper(II) chloride (CuCl2), and/or
where in method step (c) zinc oxide, preferably zinc(II) oxide, is reacted to give zinc chloride, more particularly zinc(II) chloride (ZnCl2);
and/or
where in method step (c) lead oxide, preferably lead(II) oxide, is reacted to give lead chloride, more particularly lead(II) chloride (PbCl2);
and/or
where in method step (c) cobalt oxide, more particularly cobalt(II) oxide, is reacted to give cobalt chloride, more particularly cobalt(II) chloride (CoCl2).

3 more elements

The method as claimed in any of the preceding claims, where in method step (c) silver oxide, preferably silver(I) oxide, is reacted to give silver chloride, more particularly silver(I) chloride (AgCl).

The method as claimed in any of the preceding claims, where in method step (d) the sublimation of iron chloride, more particularly iron(III) chloride (FeCl3), from the product mixture obtained in method step (c) takes place at temperatures in the range from 200° C. to 400° C., more particularly in the range from 250° C. to 375° C., preferably in the range from 275° C. to 350° C., more preferably in the range from 300° C. to 325° C.

The method as claimed in any of the preceding claims, where method step (d), more particularly the removing and/or isolating of iron chloride, more particularly iron(III) chloride (FeCl3), is carried out in a removing device, preferably in a rotary kiln, fluidized bed kiln and/or drum kiln.

The method as claimed in any of the preceding claims, where method step (c) and method step (d), more particularly the removing and/or isolating of iron chloride, more particularly iron(III) chloride (FeCl3), takes place, in particular continuously, in a common device, more particularly a rotary kiln, in particular where the common device, more particularly the rotary kiln, has a first section for the implementation of method step (c) and a second section for the implementation of method step (d), more particularly for the removing and/or isolating of iron chloride, more particularly iron(III) chloride (FeCl3).

The method as claimed in any of the preceding claims, where in method step (d) the desublimation leads to obtaining solid and/or purified iron chloride, more particularly iron(III) chloride (FeCl3).

The method as claimed in any of the preceding claims, where in method step (d) the reduction of iron chloride, more particularly iron(III) chloride (FeCl3), takes place in the gas phase, more particularly at temperatures in the range from 400° C. to 800° C., more particularly in the range from 450° C. to 750° C., preferably in the range from 500° C. to 700° C., more preferably in the range from 550° C. to 650° C.

The method as claimed in any of the preceding claims, where in method step (d) the reduction of iron chloride, more particularly iron(III) chloride (FeCl3), is carried out in a reduction device.

The method as claimed in any of the preceding claims, where the product mixture obtained in method step (d) and freed from iron chloride, preferably iron(III) chloride (FeCl3), has an iron content of less than 10 wt %, more particularly less than 5 wt %, preferably less than 3 wt %, calculated as element and based on the dry weight of the product mixture.

The method as claimed in any of the preceding claims, where in method step (d) the subsequent removing and/or isolating of chlorides of the further metals from the product mixture freed from iron chloride, more particularly iron(III) chloride (FeCl3), takes place.

The method as claimed in any of the preceding claims, where in method step (d) the subsequent removing and/or isolating of chlorides comprises removing and/or isolating of copper chloride, more particularly copper(II) chloride (CuCl2), and/or of zinc chloride, more particularly zinc(II) chloride (ZnCl2), and/or of lead chloride, more particularly lead(II) chloride (PbCl2), and/or of cobalt chloride, more particularly cobalt(II) chloride (CoCl2).

The method as claimed in any of the preceding claims, where in method step (d) the subsequent removing and/or isolating of the chlorides of the further metals from the product mixture freed from iron chloride, preferably iron(III) chloride (FeCl3) takes place in a slurrying and/or dispersing device, more particularly in a stirred tank and/or stirred reactor, and/or in a countercurrent device, preferably with in each case at least one withdrawal means.

The method as claimed in any of the preceding claims, where in method step (d) the subsequent removing and/or isolating of the chlorides of the further metals takes place such that the product mixture freed from iron chloride, preferably iron(III) chloride (FeCl3), is received, more particularly slurried and/or dispersed, in a liquid phase and/or in a liquid medium, more particularly water.

The method as claimed in any of the preceding claims, where the product mixture obtained in method step (d), more particularly the product mixture freed from iron chloride, preferably iron(III) chloride (FeCl3), and from the chlorides of the further metals, calculated in each case as element and based in each case on the dry weight of the product mixture, comprises:

gold, more particularly in amounts in the range from 1 g/t to 50 g/t, preferably in the range from 1 g/t to 40 g/t, more preferably in the range from 2 g/t to 20 g/t, very preferably in the range from 3 g/t to 15 g/t;
silver, more particularly in amounts in the range from 2 g/t to 600 g/t, preferably in the range from 5 g/t to 500 g/t, more preferably in the range from 10 g/t to 400 g/t, very preferably in the range from 15 g/t to 200 g/t.

The method as claimed in any of the preceding claims, where the product mixture obtained in method step (d) and/or in method step (e) comprises silicon, more particularly in the form of a silicon oxide, preferably silicon dioxide, and/or where the product mixture obtained in method step (d) and/or in method step (e) comprises at least one alkali metal and/or alkaline earth metal, more particularly at least one alkaline earth metal, preferably calcium, in particular where the alkali metal and/or alkaline earth metal, more particularly the alkaline earth metal, preferably calcium, is present in the form of at least one salt, more particularly sulfate, and/or in particular where the product mixture obtained in method step (d) and/or in method step (e) comprises calcium sulfate.

Method and plant for producing iron from roasted pyrites

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Claims73

Method and plant for producing iron from roasted pyrites

Life of this patent

Abstract

Claims73