DE1029842B - Process for the enrichment of iron and non-ferrous heavy metals from sulphurous iron and material containing iron oxide - Google Patents

Description

The invention relates to a process for the enrichment of iron and non-ferrous heavy metals, those in pebbles or other iron sulfide-containing ores or concentrates and iron oxide-containing material are included.

It has been found according to the invention that it can be produced by melting iron sulfide-containing material, such as pyrites or other ores or concentrates containing iron sulfide, mixed with material containing iron oxide in a closed furnace succeeds in removing the essential contents of one or both materials To remove silica, gangue, etc. in the form of a slag, while the main part of the iron, partly as FeS, partly as FeO, with most of them in the form of Sulfur compounds in other metals occurring in the material go together in a stone, which is very reactive and extremely suitable, after cooling to a suitable temperature and grinding another Processing by leaching, e.g. B. with dilute sulfuric acid to be subjected.

This means that any copper and cobalt that may be present go into the stone. Part of the zinc will also go into the stone and partly evaporate, so that this as well as sulfur vapor and the resulting gaseous sulfur compounds can be obtained from the exhaust gases.

As an iron oxide-containing material for the addition to the gravel one can expediently Fayalitschlacke or other from the oxidizing gravel melting process or the copper concentrate melting process Apply slag, and it succeeds at the same time, with the preliminary step of processing gravel and gravel concentrate the content of these previously almost worthless slag in valuable components to utilize, since the oxygen content in higher oxides of the slag is reduced with sulfur to FeO, which goes into the stone as a component and according to the literature with Fe S at 940 ° C and an Fe O content of about 42% forms a eutectic mixture.

The reactions that occur when using pebbles are presumably essentially as follows:

FeS ₂ -> - FeS + S
3 Fe ₃ O ₄ + FeS - * - 10 FeO + SO ₂
2 Fe ₃ O ₄ + S -> - 6 FeO + SO ₂
2 FeO + 3 S -h 2 FeS + SO ₂

If instead of the pebble z. B. Magnetic gravel, Fe ₇ S ₈ , processed, so less FeO is converted into FeS by the above reaction 2FeO + 3S - »- 2FeS + SO _2.

When using Orkla fayalite slag, of course, a considerable proportion of the FeO that goes into the stone comes from the fayalite, 2FeO - SiO ₂ , and from processes for the enrichment of iron
and the non-ferrous heavy metals

made of iron sulphide and
iron oxide-containing material

Applicant:

Pyror Limited,
Hamilton, Bermuda (British West Indies)

Representative: Dipl.-Ing. F. Busse, patent attorney,
Osnabrück, Moser Str. 20/24

Claimed priority:
Norway January 2, 1956

Sigurd Arthur Aannerud and Eigil Mostad,

Thamshavn (Norway),
have been named as inventors

this contained hedenbergite, CaO FeO-2SiO ₂ , come from.

Depending on the composition of the starting material, the mixing ratio is changed somewhat need to be in order to get the best result.

For Orklakies and Orkla-Fayalitschlacke the ratio 6: 5 has been found to be advantageous.

It has been found that this formed slag, which consists essentially of silica and something Consists of iron and any alkaline earth oxides, has a conductivity that is well suited for electrical melting, if care is taken that the electrodes do not get into the highly conductive stone.

It can be seen from the above reactions that sulfur vapor and SO _{2 are} evolved. In addition, when conventional graphite electrodes are used, the carbon electrodes will react with the oxygen in the slag to form CO, which will _{combine with sulfur to form COS and CS 2} , which in turn can react _{with SO 2} to form CO _{2 and S.}

To obtain sulfur vapor, the gas is circulated through a suitable cooler, but because of the formation of the above-mentioned gaseous sulfur compounds, the gas volume becomes

«09 510/154

Claims (4)

grow constantly, so that one can get the excess from the The course of the melting process is in the scheme System must remove. table drawing illustrates, in the 1 a longitudinal As a result, a certain borrowed furnace made of refractory material is gradually designated, with the composition of the circulation gas forming the electrodes 2 in the usual way protruding through the roof in addition to the sulfur vapor essentially CO ₈ , CO, 5 and with Arrangements COS and CS _{2 is} included, in addition there is any sealing, height adjustment, piecing, etc. H ₂ S as a result of the moisture in gravel and slag, (not shown) can be provided and the Bes as well as nitrogen from the air, which with the feed Dispatch with iron sulphide and iron oxide containing comes in together. ,: Material from above, as indicated by the feed pipe 3 Since this gas mixture "indicates the admission of oxygen i °. The furnace has an upper one for slag which is explosive and can cause great damage, drain 4 and for stone a lower drain 5 as well as if, for example, in an electrostatic precipitator during removal, if necessary." a special outlet 6 for fernung of zinc dust enters an ignition, there is tapping of the melt on the furnace bottom. the furnace is advantageous in the whole system a positive pressure down by means of the electrodes 2 up to about 1400 ⁰ C heated rechtzuerhalten. 15 which is the Stone 7 as the soil layer and the The stone, which is believed to be the main product of the process, slag 8 is obtained as the top layer. B. with dilute sulfuric acid is to ensure that the electrodes 2 are constantly leached ent countercurrent and also otherwise, as in the speaking deep into the slag 8 to German patent 815 108 for the resistance described there and thus suitable Temperature ratios calcinate indicated, treated, ie obtained by 20. Charging and removal can be carried out continuously by electrolytic iron production from the iron sulfate, so that mainly constant solution, roasting of the residue with oxygen from the levels for the slag surface and for the boundary electrolysis and catalytic sulfur production from the surface between slag and stone are obtained. H ₂ SI-SO ₂ . It turns out that the selective The drained stone can after appropriate leaching of the iron from the stone very far, up to 25 cooling and grinding z. B. with dilute sulfur-95%, can drift, and since the residue is acid leached and also in the rest, as above practically free of silica and gangue, is mentioned in, for the purpose of obtaining its individual valuable this case, the treatment of the residue Substantially processed components are simpler and require less oxygen, so that more melting takes place under an atmosphere of of which is left over to burn the H ₂ S. From the gas that is circulated by a fan 9 and sulfur compounds of the gas that is taken as mentioned above through a line 10 at a temperature of approximately the circulating mixture, the 130 ° C. can enter the furnace. From the gas outlet 11 of the sulfur content through combustion with a con furnace, the gas flows to an electrostatic precipitator 12 (controlled amount of air or oxygen under the filter) through a pipe 13, which can easily be obtained with a delivery of a catalyst; 35 screw 14 is provided to dust, which may be a catalysis for sulfur recovery if it settles on the walls, is used to the bottom of the filter of the liquor stage, these processes can be promoted. The gases occur with a temperature of appropriate combined. about 500 ⁰ C into the bottom of the filter, electrical As an example of the implementation of the method, let the zinc dust be statically freed from the melting of copper-containing Orklakies with Orkla- 40 on the bottom, and flow from the upper end of the fayalite slag called: filter with a temperature of about 400 ⁰ C through the Pipeline 15 to a cooler 16, where they ^{are cooled to about 130 °} C. so that the sulfur is condensed out, and from there return to the fan 45. Behind the fan, the gas line branches into a return line 10, an exhaust line 17 and a bypass line 18 which opens directly into the pipeline 13. These pipes are each provided with a valve 19, 20 and 21, of which the valve 20 is throttled so much that an overpressure is constantly maintained in the entire system; the valve 21 is adjusted relative to the valve 19 such that the temperature is maintained at the entrance of the filter to the desired value of about 500 ⁰ C. Any remaining sulfur that is condensed out in the fan 9 becomes, "_,". , ^ "", ",,,, with the liquid sulfur together from the cooler 16 About 600 kg of gravel and 500 kg of slag were removed
kg stone obtained. The difference is slag and
volatilized sulfur gases and zinc. Stone from electrical slag from electrical claims Melting process Melting process 61.5% Fe 21% Fe I _- Process for the enrichment of iron and the 29.2% S 53% SiO ₂ 65 non-ferrous heavy metals that are found in pebbles or 2.78% Cu 6% CaO other iron sulfide-containing ores or concentrates 2.0% Zn 2.5% MgO _and contains material containing iron oxide, 0.13% Co. 0.02% Cu characterized in that the iron sulfide-containing 0.5% undissolved 0% Co material mixed with material containing iron oxide The remainder is mainly oxygen 70 in a closed electrode furnace with formation Gravel analysis Fayalite slag analysis about 38.0% Fe 42.0% Fe 41.6% S. 2.8% S. 2.1% Cu 33.0% SiO ₂ 2.0% Zn 0.35% Cu 0.1% Co 1.9% Zn 10 to 16% SiO ₂ 0.04% Co Remainder CaO, MgO 4.23% CaO 1.47% Al ₂ O ₃ 0.44% MgO Rest oxygen a slag and a stone melted while any sulfur and zinc vapor expelled is obtained from the exhaust gases. 2. The method according to claim 1, characterized in that the starting material containing iron a slag obtained by oxidizing melting of pyrites or gravel concentrate is used will. 3. The method according to claim 2, characterized in that by oxidizing melting of fayalite slag obtained from copper-containing gravel is used. 4. The method according to claim 3, characterized in that that the melting process takes place under an atmosphere of circulating gas under positive pressure is carried out. 1 sheet of drawings