Allabergenov R.D., Akhmedov R.K., Mikhailov S.V. Zinc clinker - a new industrial polymetallic mineral raw material for non-ferrous metallurgy and ways of its complex processing. Electrozinc involves the development of a clinker deposit T

The purpose of the activities carried out is to assess the quality and quantitative composition product to study the possibility of developing a project for the implementation of an effective, economically sound and environmentally friendly technological scheme its disposal.

Today, about 1.575 million tons of clinker is located on the industrial site of the enterprise, formed during the period of operation of the plant from 1935 to 1992. As the chief metallurgist of the enterprise Vladimir Podunov explained, clinker is a granular material with a complex mineralogical composition, obtained as a result of dezincification of various zinc-containing products by the Waelz process. According to its properties, clinker is inert, dangers for environment does not represent. Nevertheless, the problem of accumulated waste needs to be addressed, so today Electrozinc is studying possible options for it. The initial stage of work in this direction was the conclusion in 2015 of an agreement between Sevogeologorazvedka and Elektrozink, according to which Sevogeologorazvedka specialists conduct exploration work on Elektrozink’s waste clinker to determine the volume of zinc, copper and precious metals reserves in it.

To ensure optimal conditions for conducting geological exploration work on clinker sampling, a special preparatory work- in the surveyed area, access roads with a total length of about 2 km were built, the organization's specialists developed a methodology for exploration and testing on clinker dumps, which included the construction of a dump plan with the systematization of sampling points.

Clinker samples in 10-kilogram bags were received by the Product Quality Department (QP) of the Electrozinc plant. In order to prepare samples for chemical analysis at the site of sampling and sample preparation of the UKP, the clinker was brought to the state of a powder. According to GOST, the product has passed the stages of rolling, quartering, drying, three-level grinding, grinding and screening. The resulting powder sample was quartered in a checkerboard pattern with a metal grid and packed in a special paper envelope with all sample data: number, name, date and time. A total of 258 samples were taken. In the X-ray spectral department of the central laboratory of the Product Quality Department, the samples were subjected to express analysis, after which they were sent for spectral analysis. The study of the sample for the content of zinc and copper in it was carried out on an atomic absorption spectrometer by the method comparative analysis. In parallel, the clinker was examined for the content of precious metals. According to the head of the central laboratory of the UKP, Oleg Kisiev, on the basis of the entries in the work log, a protocol was drawn up, which included the entire scope of the analytical work.

In accordance with the contract, the results of the research are expected at the end of May 2016. Based on the data received, the UMMC will make a decision on further work. Among options- reclamation or involvement of clinker dumps in processing at other enterprises. Separately, we note that since 2004, all of the current Electrozinc clinker from concentrates has been sent to UMMC enterprises for processing.

Being a consistent opponent of the location of the Electrozinc plant within the boundaries of Vladikavkaz, I gradually come to the conclusion that its preservation is beneficial not only to the owners of the production, but also to many other handicraft and semi-handicraft enterprises located in the industrial zone of the capital of the republic. Having huddled in the shadow of a metallurgical giant, it is easy to write off one's own sins as a sinner's note. And brandish this bogeyman in the face of the public. But if you sometimes look in the early morning from the height of the Sapitskaya booth in the direction of the Electrozinc, then it is far from always possible to guess its location from the columns of smoke tending to the sky. Smoke pipes around the entire perimeter of the plant. Go find out who they are.

It is clear that the “Electrozinc” “exhaust” pipes do not ozonize the air either, but if we know what can be expected from emergency emissions from this plant, then we do not even assume that fine, fine dust is brought to us from other enterprises that cook asphalt or weld metal structures, chemicals with paints or storage of building materials ... But it is precisely fine, unhealthy dust that enters the bloodstream through the lung tissue and spreads throughout the body, including the brain.

A group of scientists from the United Kingdom, the United States and Mexico have published the results of a study that indicates a possible link between ultrafine particles and the development of dementia. Nanoparticles of anthropogenic origin can penetrate the brain and accumulate there. Carried by blood throughout the body and cause diseases of vital organs. And we wonder why it is in the republic that the palette of oncological diseases, allergies, hypertension and many other diseases, derived from the harmful effects of fine dusts, is expanding. Add to this the exhaust fumes of private cars, with which all the streets and streets of Vladikavkaz are clogged from morning to evening. But for some reason we don't want to see this "log" in our own eyes...

People who have reliable information about environmental pollution in Vladikavkaz try to keep it to themselves, and distract the public consciousness with other irritants or mislead. Willingly or involuntarily, as happened now with the head of the republic Vyacheslav Bitarov.

The other day, an extensive interview of our leader, which he gave to TASS, was distributed in the Russian media. It was called "North Ossetia has every chance of becoming the Russian Silicon Valley." I will not argue about the legitimacy of this bold statement, I will dwell only on the passage of the interview dedicated to Electrozinc OJSC. We remember, of course, how resolutely Vyacheslav Bitarov declared a year or two ago about his attitude to the enterprise, which is shortening our lives. Then, obviously, economic challenges became more preferable than formal humanism, and the fate of the plant, unenviable yesterday, moved into a vague future. Probably, Bitarov has his own reasons, which he does not want to talk about yet, so I will not pedal this fact unnecessarily.

But such a quote from the interview of the Head makes me doubt either the competence of Vyacheslav Zelimkhanovich, or his sincerity. Judge for yourself:

“For us, the most important from an environmental point of view is not so much the emissions of Electrozinc, but the dump clinker that the enterprise has accumulated. Public organizations put the question point-blank and demand that Electrozinc leave the region. But then what are we going to do with millions of tons of waste, which one way or another will remain after many years of operation of the enterprise? Nobody has an answer to this question. Now we have already reached an agreement with the management of the enterprise, and starting from 2016 they are exporting clinker, and every year in an increasing volume.”

That is, all the evil, it turns out, is in the clinker?! How then to understand

General Director of Electrozinc JSC Igor Khodyko, who recently told reporters that “the clinker itself is absolutely harmless. It does not dissolve in water, does not burn and belongs to hazard class 4 waste, and, most importantly, does not affect people”?

I agree, perhaps, with the head of the plant, since he has been in metallurgy for 27 years, where he started with working specialties and has grown to the captain's bridge. But I will add on my own that the clinker with which they are now scaring us, probably, did not accidentally accumulate in about equal shares million tons not only on the territory of Electrozinc, but also outside it, on Promyshlennaya Street. And if UMMC exports factory dumps to its Ural factories, then it will not be so easy to withdraw the other part. It's about not about transportation. The fact is that, according to some reports, millions of tons of clinker on the other side of the factory fence are nothing more than a pledge value for one of the state financial institutions. That is, for this clinker, someone once received a large cash loan for the republic. And it still hasn't paid off. And each ton of clinker is credited, I'm afraid to make a mistake, at a price of one hundred to three hundred dollars. Klondike, in a word!

As for the clinker on the territory of Electrozinc, they learned how to extract rare earth metals, including gold, from it in the Urals. Therefore, its processing brings not only profit, but also creates new jobs. And we don’t need to rub thoughts about someone’s altruism: a greedy capitalist won’t let a fly fly by for free! Although, they say, our home-grown chemists have long figured out the tricky technologies themselves and trump in crowns made of gold “washed” in dumps.

Once again I will say that I support the closure and transfer of Electrozinc with both hands, although in childhood we inhaled thick clouds of its emissions every day. And there was also a bike that sulfur dioxide increases the sexual activity of a man. He breathed and - in bed! But then again, why don't we associate our illnesses, say, with tap water, believing in the well-established delusion about its crystal purity? City water supply networks are in such a state that it is better to boil the water beforehand. And that's putting it mildly. But changing pipes that have been in the ground for more than half a century at a time is more expensive than moving Electrozinc!

Actually, we are talking not only and not so much about "Electrozinc" and other pollutants of the atmosphere of Vladikavkaz, but about the right of the people to know the truth, no matter how bitter it may be. And the authorities should be interested in this themselves, so as not to multiply ridiculous rumors and speculation about themselves. People can be deceived once or twice, but it is impossible to deceive forever!

//Uzbek Chemical Journal of the Academy of Sciences of the Republic of Uzbekistan. - Tashkent. 2012. No. 3.S.43-49.State Enterprise "Central Laboratory" of the State Committee for Geology of the Republic of Uzbekistan,Institute of General and inorganic chemistry AN RUz.

UDC 669.054.8:669.5

Currently, zinc clinker produced by Almalyk MMC OJSC is accumulated in dumps and processed in small volumes: hundreds of thousands of tons of clinker are sent to dumps annually, and only a tenth of them are processed together with copper-containing raw materials using the today's basic technology of reflective melting. The economic irrationality of this technology is obvious for the following reasons: high energy consumption of melts (due to the use high temperatures: 1000-1200OS); dust and gas emissions that require the cost of their capture and purification; slag heaps; low complexity of processing due to losses of copper, zinc, iron and precious metals with slags. This situation is not least due to the lack of competitive clinker processing technology. A promising technology can only be considered if complex processing clinker with the extraction of iron, non-ferrous and precious metals and taking into account environmental considerations: the importance of freeing land from the "mountains" of old clinker, which causes erosion and contamination of land with harmful elements (arsenic, lead, etc.).

Therefore, the analysis of existing clinker processing methods and their improvement are of great scientific and practical interest from the point of view of finding a competitive method for the complex processing of this raw material. According to mineralogical and technological properties, clinker is classified as a new sulfide-oxide-poly-metal industrial type of mineral raw materials with a high content of precious metals, which is a chemically resistant material for processing. This raw material is difficult to process because it consists of sulfides, fayalite, metasilicate and ferrates, and also because it is highly diluted with waste rock (free carbon, silica, calcium and magnesium oxides, alumina).

Clinker is a man-made raw material containing mainly iron (24-29%), non-ferrous metals, the main of which are zinc (1.2-3.2%), copper (1.2-2.5%), lead (0 .7-0.9%) and noticeable amounts of noble elements. Therefore, it is economically more profitable to consider clinker as a raw material for the extraction of copper and zinc, as well as iron and lead middlings enriched with precious metals, in compliance with the principle of waste-free technology.

As can be seen from Table 1, the main part of the minerals present in the clinker consists of a silicate phase (glass, fayalite, etc.), which contains the eutectic of copper, zinc, lead and other minerals. Sometimes, in a subordinate amount, there are ingrowths of aggregates of coke (coal) with metallic iron. Part of the minerals that make up old clinkers, under the influence precipitation and burning, transformed into Various types compounds: hydroxides, carbonates, sulfates, phosphates, arsenates, chlorides, bromides, iodites of iron, silicon, sodium, calcium, copper, arsenic, lead, zinc, antimony, silver. At the same time, part of the gold is released from the structure of sulfides and other minerals and becomes coarser.

Table 1

Phase composition of old clinker [2]

Mineral composition
1. Glass K(AlO 2)(SiO 2) 3 , Na 2 0.CaO.6SiO 2 Fayalite Fe 2 SiO 4 , clinoferrosilite or metasilicate FeSiO3
2. Pyrrhotite FeS
3. Limonite 2Fe 2 O 3 .3H 2 O
4. Magnetite Fe 3 O 4
5. Zinc ferrates ZnO. Fe2O3 (double oxide with spinel structure), zinc silicates Zn 2 SiO 4
6. Copper sulfides (bornite Cu 5 FeS 4 , chalcosine Cu 2 S , chalcopyrite CuFeS 2 )
7. Iron metal Fe
8. Copper ferrates CuFeO 2
9. Copper metal Cu	0,01

The development of a method for non-waste integrated processing will allow us to evaluate the technology for recycling old clinker as an environmental measure that will lead to the release of land plots, where clinker dumps are stored, and will allow, to some extent, to expand the raw material base of non-ferrous metallurgy. Special studies mineral composition clinker showed [2] that 97% of copper is present in resistant forms: 90% of this copper is in the form of bornite and chalcocite, 7% is in the form of chalcopyrite, 2.4% is copper ferrate and 0.6% is metallic copper ; iron is almost completely found in stubborn hard-to-open forms in the form of fayalite, metasilicate and ferrates with a spinel structure [spinels are double oxide-oxosalts, chemically inert, not having a salt-like character, crystal lattice which the metal is present in different valences, for example, in the usual spinel Fe 3O 4 there are Fe 2+ and 3+]; zinc is also difficult to leach: in the form of ferrates with a spinel structure and silicates.

Solve the problem of complex and efficient processing Clinker dumps based on the use of various pyrometallurgical methods have inherent pyrometallurgy disadvantages (energy intensity, dust and gas emissions, slag dumps, etc.), which do not allow qualifying the technology as environmentally friendly and highly profitable. For the same reasons, repeated attempts to build combined schemes based on the methods of mechanical enrichment with the separation of concentrates and middlings of copper, iron, and precious metals from clinker, followed by their pyrometallurgical processing, were unsuccessful [3, 4].

Modern methods of hydrometallurgical technology: autoclave leaching, oxidative catalytic opening, etc. have not yet gone beyond the scope of exploratory laboratory research.

Hydrometallurgical technology proposed waste-free processing clinker with its complete utilization and high recovery in marketable products, respectively, Au and Ag by 80-90 and 55-65%% in the form of Doré alloy (1.7% Au and 98% Ag); Cu 90-95% in the form of copper cement powder (95% copper); coal (coke) by 95%, which is an energy fuel; silicate tailings (70% silica) and gypsum hydrate cake suitable for use in the construction industry (if necessary, it is possible to extract zinc from silicate tailings by hydrometallurgical means, and lead by pyrometallurgical means). The essence of the technology lies in the sequential and selective separation of copper (as well as zinc) from crushed clinker, then from the solid residue of gold (silver) washed with water. Copper is leached with sulfuric acid at 60-80°C and cemented with iron scrap. Gold is isolated by sorption cyanidation (using A100/2412 anion exchanger followed by thiourea desorption), and coal (coke) is isolated from waste pulp by flotation. The disadvantage of the method is the low extraction of copper into the solution (no more than 70%), the use of cyanidation, etc.

It is shown that the traditional schemes of hydrometallurgical processing of calcined zinc materials with an increased iron content in them do not provide a high extraction of zinc and copper into the solution, for the reason that copper ferrates (CuFeO 2) and zinc (ZnO .Fe 2 O 3) are formed during roasting c about the structure of spinels, which are resistant to chemical decomposition forms. The authors propose an autoclave sulfuric acid leaching of clinker at 110-150°C, pre-crushed to a grain size of 200 mesh (-0.074 mm), an oxygen pressure of 6 atm (0.6 MPa), T: W = 1: 4 and a process duration of 2-3 hours. In this case, the extraction of zinc into the solution is 98-99%.

A new hydrometallurgical process for separating zinc from a material obtained in an electric smelter involves melting an intermediate product previously washed with water at 350 ° C for 1 hour and leaching it in an alkaline solution with the dissolution of zinc and lead. Lead is precipitated from the solution with sodium sulfate, and zinc is isolated by electrowinning.

There is a known method for extracting copper and zinc from clinker in the form of a sulfate solution, which is sent to zinc production, and the resulting lead sulfate cake is shipped to lead production. The method includes roasting with a CaCl 2 chlorinator with separation of sublimates of non-ferrous metal chlorides, their hydrochloric acid irrigation and precipitation of non-ferrous metal hydrate cake by neutralization of wet sublime trapping solutions with lime. The cinder after firing, containing about 0.2% copper, 0.3% zinc, 0.1% lead and almost all noble metals, is sent to the dump, and the hydrate cake is dissolved in the spent electrolyte to obtain a sulfate solution of copper and zinc and a sulfate cake lead. The main disadvantages of the method are the loss of precious metals with waste cinder, the complexity and multi-stage scheme associated with the use of chloride sublimation and hydrochloric acid wet trapping of sublimates, the use of an expensive and scarce component - hydrochloric acid, which also requires special safety measures.

We have developed new way, including low-temperature sulfatizing clinker roasting, which makes it possible to transform "resistant" minerals into soluble sulfate salts of copper and zinc, which are selectively extracted into solution in the form of stable ammoniates Cu (NH 3) 4 SO 4 and Zn (NH 3) 4 SO 4 by ammonia leaching. While iron in the form of Fe (OH ) 3 and the main part of lead in the form of PbSO 4 remain in the cake.

The essence of sulfatization of clinker using concentrated sulfuric acid is as follows: the clinker is granulated to a fraction of 5 mm in H 2 SO 4 by separate feeding of the components to a rotating bowl granulator; further, the granules are subjected to low-temperature firing in equipment made of ordinary steel (furnaces KS (“fluidized bed”), multi-hearth furnaces, and other units can be used as equipment). The chemistry of the processes occurring in this case with the formation of a sulfate cinder is presented as follows:

Fe 2 SiO 4 + 4 H 2 SO 4 \u003d Fe 2 (SO 4) 3 + SiO 2 + 4 H 2 O + SO 2 (1),

FeSiO 3 + H 2 SO 4 = FeSO 4 + SiO 2 + H 2 O (2),

2 FeS + 4 H 2 SO 4 + 3 O 2 \u003d Fe 2 (SO 4) 3 + 3 SO 2 + 4 H 2 O (3),

Fe 2 O 3 + 3 H 2 SO 4 \u003d Fe 2 (SO 4) 3 + 3 H 2 O (4),

ZnO.Fe 2 O 3 + 4H 2 SO 4 \u003d ZnSO 4 + Fe 2 (SO 4) 3 + 4 H 2 O (5),

Cu 2 S + 2 H 2 SO 4 + 2 O 2 \u003d 2 CuSO 4 + S O 2 + 2 H 2 O (6),

CuFeO 2 + 2 H 2 SO 4 = CuSO 4 + FeSO 4 + 2 H 2 O (7),

2 Fe + 3 H 2 SO 4 + 3/2 O 2 \u003d Fe 2 (SO 4) 3 + 3 H 2 O (8),

Cu + H 2 SO 4 + ½ O 2 \u003d CuSO 4 + H 2 O (9).

In the process of ammonia leaching of the cinder, copper and zinc are separated from iron as a result of the dissolution of the former and the precipitation of the latter:

With uSO 4 + 4 NH 4 OH \u003d Cu (NH 3) 4 SO 4 + 4 H 2 O (10),

ZnSO 4 + 4 NH 4 OH \u003d Zn (NH 3) 4 SO 4 + 4 H 2 O (11),

PbSO 4 + NH 4 OH \u003d NH 4 (PbOH.SO 4) ( partially ) (12),

Fe 2 (SO 4 ) 3 + 6 NH 4 OH = 2 Fe (OH) 3 + 3 (NH 4 ) 2 SO 4 (13),

FeSO 4 + 2 NH 4 OH \u003d Fe (OH) 2 + (NH 4) 2 SO 4 (14),

Fe 2 (SO 4 ) 3 + 6 NH 4 OH = Fe 2 O 3 + 3 (NH 4 ) 2 SO 4 + 3 H 2 O (15).

The pulp after leaching in the presence of flocculants (PAA, unifloc, etc.) settles well and is filtered with the formation of a solution of copper and zinc and a solid residue that accumulates iron, lead, precious metals and gangue. In essence, the proposed mode of ammonia leaching of sulfate cinder is reduced to salt ammonia leaching with (NH 4) 2SO 4 agent, which provides selective precipitation of iron and complete solubility of copper and zinc.

Copper and zinc from the solution, according to the proposed method, is precipitated by hydrothermal sulfiding into a collective sulfide concentrate, which can be processed in copper or zinc production. The chemical essence of sulfiding is expressed by the following reactions:

Cu (NH 3 ) 4 SO 4 + Na 2 S = CuS + 4 NH 3 + Na 2 SO 4 (16),

Complete disposal of stale clinkers dumps with the production of copper and zinc middlings in the form of a collective concentrate.

At the same time, the technological chain of clinker processing to obtain a solution of copper and zinc, in comparison with the known method, is as short and simple as possible: "sulfatizing roasting - ammonia leaching".

The efficiency of the technology is due to the combination of the following metallurgical methods developed by us for the first time: milling old clinker, mixing it with concentrated sulfuric acid to obtain granules, roasting granules, grinding cinder in a ball mill and leaching using ammonia water. In this case, copper, zinc and traces of iron are extracted into the solution. The extraction of copper and zinc is at least 90-95%.

To isolate copper and zinc from an ammonia solution, it is acidified to pH 5-6 with sulfuric acid at room temperature and treated with a sulfidizer solution (Na 2S ) with live steam supply and gas phase suction. The method has been worked out on a semi-industrial scale and ensures complete precipitation of copper and zinc in the precipitate. At the same time, in the sulfide precipitate - the collective concentrate - the copper content is 30-34%, zinc 32-35%. Extraction of copper into concentrate reaches 93-95% and zinc 91-93%.

The mother liquor after precipitation of the collective concentrate of copper and zinc is a solution of sodium sulfate salt. This salt can be separated from the solution by evaporation-crystallization and shipped as a raw material for the glass industry or the production of detergents.

For the separation of copper and zinc in solutions, the method of fractional crystallization or fractional hydrolytic precipitation can be used due to different precipitation pH values.

The method of separation by carburizing copper on zinc metal powder is justified to obtain a sediment of cemented copper and a solution of zinc.

A significant improvement in the technical and economic indicators of the technology can be achieved by separating copper and zinc from ammonia solutions by distilling ammonia with subsequent regeneration of ammonia water.

Promising is the use of sorption technology for the extraction of copper and zinc with the production of sulfuric acid eluates (desorbates) - solutions of these metals, suitable both for electroextraction and for the isolation of vitriol or metal powders.

The method makes it possible to evaluate the technology of disposal of stale clinker as an environmental measure that will free up land plots where clinker dumps are stored and ensure the expansion of the raw material base of non-ferrous metallurgy. The proposed method of clinker processing ensures the complete utilization of stale clinker dumps with the extraction of copper and zinc in the form of intermediate products suitable for processing in the existing scheme of Almalyk MMC OJSC; concentration at the same time in the solid residue of almost the entire mass of iron, lead, waste rock and precious metals; selective separation of iron from the solid residue with the maximum concentration of lead and precious metals in the final solid residue - the concentrate of precious metals.

conclusions

Utilization of zinc production clinker can be effective only if it is comprehensively processed. For the Almalyk Mining and Metallurgical Complex, which includes copper-smelting, zinc and lead plants, such processing is beneficial with the separation of copper and zinc, as well as lead, enriched with precious metals, middling products from clinker, expanding the raw material base of the above-mentioned enterprises. In addition, the production of an iron oxide semi-finished product from clinker contributes to solving the raw material problem of the local ferrous metallurgy.

To solve the problem of complex processing of clinker, a mixed pyro-hydrometallurgical technology is recommended. At the same time, the pyrometallurgical section primarily ensures the transfer of hard-to-open forms of the main clinker components into water-soluble salts - zinc, copper and iron sulfates, without affecting noble metals. The hydrometallurgical section of the technology makes it possible to selectively extract zinc, copper and iron into independent products suitable for processing at existing non-ferrous and ferrous metallurgy enterprises of the Republic of Uzbekistan.

8. Mitov K.L. and other Method of processing metallurgical clinker. Patent 60786, 1996 (Bulgaria).

9. Pirkovsky S.A., Smirnov K.M. and others - RF Patent No. 94015041, 1994.

10. Naboychenko S.S. Balatbaev K.N. Autoclave sulfuric acid leaching of zinc concentrates. - Non-ferrous metals, 1985, No. 2, pp. 23-25.

11. A new hydrometallurgical process for separating zinc from a finely dispersed fraction of a material obtained in an electric smelter - RJ "Metallurgy". Consolidated volume 15, 2002, No. 6, ref. 02-06-15G127 (p. 13, England)

12. Tarasov A.V., Zak.M.S. Extraction of valuable components from clinkers of zinc production. - "Color metallurgy", 1990, No. 6, pp. 46-48.

13. Allabergenov R.D., Karimov B.R., Chizhenok I.G., Mikhailov V.V. The method of processing clinker dumps of zinc production. - Decision of the State. Pat. The Office of the Republic of Uzbekistan on the issuance of an international patent for an invention dated 03/27/2009 according to an application for a patent No. IAP 20060345 dated 09/22/2006

14. Extraction of a mixture of lead with tin and separately copper with zinc from dust from the production of brass - RJ "Metallurgy", 1972, ref. 10G380.

After joining the Ural Mining and Metallurgical Company in 2004, the topic of recycling old-fashioned clinkers smoothly flowed onto the shoulders of the new owner. Moreover, today it has become a weighty topic of environmental speculation about the harm we cause. om enterprise, despite the fact that since 2004 it was the Ural Mining and Metallurgical Company that completely stopped storing current clinkers on the territory of the plant and began to send middlings to other plants of the holding in full.
There is no logic in this, but speculation only grows stronger year by year.
We wanted to look into this issue in more detail. Moreover, it has a history, both old and new. There is also a significant amount scientific research, both in terms of the harmfulness of this middling product for the ecology of the city of Vladikavkaz, and in terms of the prospects for its disposal.
When the so-called "specialists" give examples of successful processing of clinkers by enterprises outside of Ossetia and even Russia, they forget one essential fact. Clinkers are both "rich" and "poor", which is due to the feedstock and the technological features of its processing. Clinker with a high content of copper (more than 1%), gold (more than 1 g/t) and silver (more than 120 g/t) is considered rich. The main method of processing "rich" commercial clinker is mine reduction smelting together with copper-bearing raw materials, in which all valuable components are converted into matte and recovered.
If the content of copper and precious metals is lower, then the clinker is considered "poor". And so far he does not find industrial applications to extract its valuable components due to the low technical and economic efficiency of the process. In other words, its processing is unprofitable. Therefore, the poor clinker in the practice of all enterprises is sent to the dump farm.
This is exactly the fate of the “poor” clinker of the Electrozinc plant.
Soviet, and then Russian eResearch institutes have repeatedly tried to offer technologies for the processing of poor clinkers. In 1964, the technology of joint clinker enrichment with fiagdon ore was proposed by SK GMI. In 1971, VNIITsvetmet developed a technology for clinker enrichment by flotation followed by magnetic separation of flotation tailings. In 1974, the Institute of Metallurgy of the Ural Scientific Center of the USSR Academy of Sciences designed specifically for Electrozinc a plant for the complex processing of clinker by magnetic separation and coal-sulfide flotation. In 1982, a pilot plant for clinker processing was designed at the Kavkaztsvetmetproekt Institute. For many years, the Gintsvetmet Institute has been conducting research on the chlorine sublimation roasting of clinker.
None of the projects was able to achieve a payback to be used in production.
The problem of clinkers processing has been studied by specialists of the Ural Mining and Metallurgical Company since 2004. Since none of the clinker processing options proposed by the Research Institute was of industrial importance, it was proposed to utilize it as a material for paving, organizing a site on the territory of the plant, etc. However, another problem arose here.
The fact is that for all the "poverty" of the stale clinker "Electrozinc" it contains silver. According to various sources, from 100 to 200 grams per ton. This silver in clinkers is in a dispersed state, heterogeneous in content in dumps different years, that is, it also has no industrial significance. But, nevertheless, it is a precious metal. And the utilization of clinkers turned out to be impossible without special permission for this from the Gokhran of Russia.
Speaking to the Government and Parliament of North Ossetia in February 2012, CEO UMMC Andrey Kozitsyn touched upon this topic separately.
- Given the presence of precious metals in the clinker, the situation has not yet been resolved, although at one time I even discussed this issue with Russian Finance Minister Alexei Kudrin. Our position is simple: convert the clinker into an inert state, crush it and take it out for disposal. And we are ready to start this work even tomorrow. However, here we need the help of the republican authorities. It is necessary to somehow negotiate with the Ministry of Finance, - Andrey Kozitsyn explained.
Such a decision, according to the specialists of the Ural Mining and Metallurgical Company, would remove this issue from the agenda and would not affect environmental situation in the republic. Studies conducted at the beginning of 2012 by the Ural GIProCentre (Chelyabinsk) showed that“... clinker is a chemically neutral, fire and explosion-proof substance that cannot decompose under atmospheric conditions with the release of fire and explosion hazardous products, form toxic compounds with water and cause corrosion of metals, and is not a dangerous cargo. It is assigned to the 4th sanitary class of waste, for which dangerous properties not installed. This type of waste cannot harm the environment and affect the properties of groundwater.”
It should be added that, for example, the clinkers of Ust-Kamenogorsk have been successfully used in road surfaces for several years.
The government of North Ossetia, having connected to this topic, proposed other options for solving the problem, incl. inclusion of the topic of Electrozinc clinkers in the federal program "Elimination of the accumulated environmental damage of past years for 2014-2025".
At the beginning of 2013, Electrozinc specialists prepared all the documents necessary for the decision of the Ministry of Natural Resources of the Russian Federation on the inclusion of Electrozinc clinkers in the federal target program and transferred to Moscow.
And the last.
Now that the problem of clinkers has been explained both in industrial and environmental terms, the question remains, what is the subject of speculation on this topic? It seems to us that this is a purely aesthetic aspect.
The fact is that the dump field of the Electrozinc plant was designed in such a way that it was located on the opposite side from the city of Vladikavkaz. But over the years of the expansion of the city, the clinkers towering over the perimeter of the plant actually ended up in the area of ​​\u200b\u200blife and activity of the population.And the general landscape of the city is not decorated at all.

July 8, Vladikavkaz. At the industrial site of Electrozinc OJSC (an enterprise of the UMMC metallurgical complex), shipment of clinker from dumps accumulated by zinc production over eighty years of operation has begun. The start of shipment of reserves of the man-made deposit from the territory of the republic is another result of the fruitful interaction between the management of North Ossetia-Alania, UMMC and the Electrozinc plant to resolve the most topical issues activities of the Vladikavkaz enterprise.

The first trial batch of dump clinker in the amount of 10,000 tons, which is about 160 wagons, will be processed in the Urals. In addition, this year Electrozinc will send another 10 thousand tons of dump clinker to the UMMC copper-smelting enterprises, which also have the necessary capacities. In general, Electrozinc, in case of an increase in the needs of partners, is ready to ship up to 50 thousand tons annually. Also, according to Igor Khodyko, there is an active teamwork UMMC and Electrozinc to find alternative ways to solve the problem of accumulated waste, among the options being considered is a reclamation project, as well as shipment of the product to cement plants.

To make sure that the Vladikavkaz enterprise actually fulfills its obligations and personally see the start of work on the removal of dumps, on July 6, Taimuraz Tuskaev, Acting Chairman of the Government of North Ossetia-A, arrived at Electrozinc. Accompanied by Igor Khodyko, General Director of Electrozinc JSC, and Oleg Dauev, Deputy Minister of Industry and Trade, he proceeded directly to the shipment site.

This is the dump clinker that we have prepared for shipment to our partners, - Igor Khodyko explained to the guests, - at the same time, it should be noted that today's, the first, shipment under the contract was preceded by a large set of measures, which included exploration work on clinker, an assessment of copper reserves , zinc, iron and precious metals, sample analysis carried out by specialists of the Sevosgeologorazvedka, as well as the development based on the results of economically sound calculations for the processing of dumps and, further - directly preparing commercial offer for our partners.

About 1.8 million tons of clinker, formed during the period of the plant's operation from 1935 to 2003, is located on the industrial site of the enterprise with an area of ​​about 4 hectares. Clinker is a product obtained as a result of the dezincification of various zinc-containing products by the Waelz method, it has a complex composition and is a granular, chemically neutral and fire and explosion-proof material; referred to the 4th sanitary class of waste for which hazardous properties have not been established.

Today we have witnessed a truly significant event at Electrozinc - an event that the republic has been waiting for a long time, - Taimuraz Tuskaev emphasized during the meeting, - we see that the enterprise systematically fulfills the agreements reached between Vyacheslav Zelimkhanovich (Bitarov, Acting Head of North Ossetia-Alania ) and the management of the UMMC. We see how seriously they take the need to solve the entire range of agreed tasks here, we see the readiness of the enterprise to meet constructive dialogue in order to achieve peace and stability in our republic. We are counting on such a position in the future, because there is still a lot of work ahead, including on the complete cleaning of the plant’s territory from dumps, on increasing the enterprise’s tax deductions to the budget of the republic, active participation"Electrozinc" in social life North Ossetia.

Vyacheslav Bitarov, Acting Head of North Ossetia-Alania, also assessed the interaction with the management of the UMMC and the shipment of the first batch of clinker from Electrozinc:

As of today, all of our agreements that were reached at the meeting with Andrey Anatolyevich Kozitsyn (General Director of the Ural Mining and Metallurgical Company) are being implemented in accordance with the deadlines. We see that the export of clinker has begun, which has accumulated over many years, and this is now one of the main issues. There is a phased closure of the lead production, the final stop of the shop is planned in September. We hope that in the future all the agreements reached with the management of the UMMC will be implemented in a timely manner.

It should be noted that since 2004, Electrozinc has not stored all the current clinker on the territory, but sent it to the UMMC copper-smelting enterprises for further processing.