SMM News:-- an exclusive interview with Wen Jinde, chief engineer and professor-level senior engineer of Gaolang International Industrial Co., Ltd.
With the rapid development of China's aluminum industry, the serious shortage of bauxite resources in China has become increasingly prominent. according to Chinese customs statistics, the import of Chinese bauxite in the first half of 2020 was about 58.3 million tons, an increase of 30.28% over the same period last year. With the gradual emergence of the current situation that China's bauxite is highly dependent on imports, how to take the road of bauxite development in the future, how to reduce the risk of imported bauxite, and how to scientifically and rationally develop and utilize resources and other hot topics have become the focus of the industry.
After the just-concluded 2020 (the first) China Aluminum Industry chain High quality Development Summit, the reporter interviewed Wen Jinde, chief engineer and professor-level senior engineer of Gaolang International Industrial Co., Ltd. He has been in the industry for 36 years, won the National Science and Technology Progress Award and received a special subsidy from the State Council government. From workshop technicians to senior experts in the field of bauxite and alumina, Wen Jinde has his own unique views on the development of the aluminum industry.
Reporter: how to view the trend of domestic bauxite market in the future?
Wen Jinde: with the rapid development of China's aluminum industry, the annual output of alumina in China has broken through to 70 million tons in one fell swoop from more than 4 million tons in the past decade, accounting for 54% of the total output of alumina in the world. However, the proved reserves and retained reserves of bauxite in China only account for 3% and 5% of the world's proven and retained reserves, so it is difficult to support more than 50% of the production of alumina in China. Therefore, in the case of serious shortage of domestic bauxite resources, it will be inevitable for China to rely on overseas bauxite resources in the future.
At the same time, China's imports of bauxite have increased at an annual rate of 20% in the past five years. In 2019, China's imports of bauxite accounted for 53.8% of the total consumption of alumina ores, while in the first half of 2020, China's bauxite imports reached 58.3 million tons, an increase of 30.28% over the same period last year. Among them, the import of bauxite in June alone was about 10.4 million tons, an increase of 9.37% month-on-month and 17.6% over the same period last year. With these changes in the bauxite market, China's alumina production has entered a new pattern dominated by imported ores, which is dominated by imported ores. At the same time, the domestic bauxite market structure is about to turn into a turning point.
Reporter: does imported bauxite have more advantages than domestic bauxite?
Wen Jinde: yes, imported bauxite to produce alumina has advantages in energy, society, economy, market and other aspects.
From the energy point of view, the use of imported bauxite can reduce the comprehensive energy consumption of alumina by more than 1/4. Imported bauxite is generally mainly diaspore type, some contain a small amount of diaspore, the alumina leaching process can be at low temperature (145 ℃) or medium temperature (230 ℃), and the production of alumina does not need to add lime, while domestic bauxite is diaspore type, the leaching process must be carried out at high temperature (270 ℃), which has limitations.
From the perspective of social benefits, the harm of imported bauxite to the environment is relatively small and more environmentally friendly. In general, the red mud output rate of imported ore after alumina production is 1 ton / ton, while that of domestic ore production alumina red mud is 1.5 tons / ton. Red mud treatment is a "worldwide" problem, the current treatment methods still basically rely on storage, not only occupy a large area of land, but also easy to produce risks, the relatively small red mud production rate is very friendly to the environment. In addition, the mining of domestic ores also has a great impact on the local environment, not only affecting the change of the groundwater level, but also producing about 10% of the massive accumulation of tailings, affecting the surface environment.
From the perspective of economic benefits, relevant data show that the average cost of some enterprises using imported bauxite to produce alumina in Shandong Province is about 300 yuan / ton lower than that of enterprises producing alumina from domestic ores in Shanxi Province.
From the market point of view, there is a giant monopoly in domestic bauxite resources. the development of imported bauxite can promote more companies to have resources and competitiveness, break the current domestic price alliance, and make the market more diversified and flexible.
In a word, it is an inevitable trend to use imported bauxite to produce alumina, and even in the near future, the proportion of domestic imported bauxite in alumina production will gradually reach more than 80%. Therefore, accelerating the study of the distribution, exploration and exploitation of global aluminum resources is of great significance for the development of China's aluminum industry, improving the level of national economy and ensuring the development of national strategy.
Reporter: what are the characteristics of bauxite imported from different countries? What technologies and production strategies can be solved?
Wen Jinde: China has rich sources of imported ore. At present, it has formed a supply pattern dominated by Guinea, Australia and Indonesia, supplemented by many countries. There are mainly Montenegro bauxite, Indonesian bauxite, Guinean bauxite, Jamaican bauxite, Australian bauxite and so on.
Heishan bauxite has the characteristics of high aluminum and low silicon, few impurities and stable quality. its advantage is that Heishan bauxite is diaspore type, and diaspore is about 8%, which is very close to domestic ore and can be directly used in high temperature Bayer process production line. Heishan mine is a cave mining with low moisture and no freezing in winter, which is especially suitable for alumina enterprises in the north. At the same time, the content of organic matter in Heishan mine is very low, no special treatment process is needed for long-term use, and the sulfur content is low. It can be mixed with local high-sulfur ore.
Indonesian bauxite is mainly a resource in West Kalimantan, and its advantage is that it is easy to dissolve, especially suitable for low temperature Bayer process alumina, and has low leaching temperature, low comprehensive energy consumption and low organic matter content, so it does not need to be treated separately for long-term use. But in addition, the ores in this area also have disadvantages such as high moisture content of washing ore and the need to simply transform the high temperature line, which will increase the production cost of enterprises to a certain extent. The ores in this area are mainly divided into ores with a grade of 49% of aluminum oxide, 4% of silicon dioxide and 2% of active silicon. They are very high-grade minerals in the bauxite market in Indonesia, which are suitable for use in low-temperature production lines and high-temperature production lines. The ore with a grade of 49% aluminum trioxide, 8% silicon dioxide and 3.5% active silicon is also a high-grade mineral product in the bauxite market in Indonesia, which is especially suitable for low-temperature production lines. The ore with a grade of 47% aluminum trioxide, 10% silicon dioxide and 5% active silicon is a low-grade mineral product, which will increase the consumption of 250kg ore and 60kg caustic soda in the production process, thus increasing the processing cost of alumina and producing more red mud of 150kg. But at the same time, the moisture content of the washing ore in this area is on the high side, the north area should pay attention to anti-freezing, and the high temperature line needs to be reformed simply, and the direct use will have an impact on the economy of the enterprise.
The Jamaican bauxite deposit is close to the surface and is easy to be mined in the open pit, and the mine is located close to the port for easy shipping. Its ore has the advantages of low silicon, good stability, no lump of ore, Amax S up to 30, low external water content, suitable for northern enterprises to use in winter, and contains a certain amount of boehmite, which can be directly mixed and used in high temperature production line. The disadvantage is that the content of organic matter is on the high side, and long-term use alone requires the production enterprise to treat it.
The total storage amount of bauxite in Guinea is estimated to be more than 24 billion tons, and mineral sites are distributed almost all over the country, of which 7.4 billion tons have been proved, accounting for 1/3 of the world's proven reserves, ranking first in the world. It is characterized by easy access to mineral sites, basically no need to peel off non-mineral soil, open-pit mining, high ore grade, including 45%-60% alumina and 1%-4% silicon dioxide, and mineral storage is concentrated. Generally, a mining site is about several million to several billion tons. The advantage of ore is large reserves, sufficient supply, some of the ore dihydrate boehmite is low, which can be used in low temperature production line, but most of the ore is suitable for high temperature production line treatment, only need to control medium temperature operation. The difficulty in production is that the low temperature treatment needs to transform the high temperature line, the content of some organic matter is on the high side, and the organic treatment process is needed.
Australia's bauxite deposits are concentrated in three areas: northern Queensland, Wepa (Weipa) and Gove (Gove) near (Gulf of Carpentaria) in the Gulf of Carpentaria; (Darling Ranges), the Darling Mountains south of Perth, WA, the two largest proven and exploitable bauxite deposits in the world; and (Mitchell), Mitchell Heights in northern WA. Among them, Gough mine is mainly gibbsite, which can be treated by low temperature line, most other ores are mixed type of three water and one water, and high temperature line can be used. However, the content of organic matter in the ores in this area is very high, and some ores have high requirements for the sedimentation of red mud because of the low Amax S of some ores.
Bauxite in other countries also has different characteristics and is also suitable for different alumina production. Brazilian bauxite is mostly of gibbsite type, and its moisture content is lower than that of Indonesian ore, which is basically close to Australian ore, so it is suitable for low temperature line blending. The export of bauxite in India is mostly in the west, and it is also of gibbsite type, which is basically massive and difficult to grind, and uneven grinding will affect the settlement. The particle size of Solomon bauxite is similar to that of Jamaica ore, which is of gibbsite type and has a high content of organic matter, so it is suitable to be mixed in low temperature line. Malaysian ore is close to Indonesian ore and can reach a better grade after washing, and some of the ore can be used without washing. Ghanaian bauxite has a high Ahammer S, which can reach more than 30, and can be used in all production lines, but the output is small and the price is on the high side. Turkish bauxite has a high content of titanium dioxide (12%) and calcium oxide, which can be mixed in high temperature line, but alumina is also difficult to dissolve.
Reporter: in the face of the current situation that China is highly dependent on imported bauxite, will we be exposed to the risks brought by the importing countries due to policy changes and other factors in the future, and how to deal with them?
Wen Jinde: with the increase of dependence on imported ore, ensuring the supply of concentrate ore will be our common goal and vision for some time in the future. However, it should be noted that with the improvement of China's comprehensive national strength, China's influence in the world is increasing year by year, which will provide strategic guarantee for China's imported ore supply to a certain extent; at the same time, the enhancement of China's control in the South China Sea has also played a great role in ensuring the transportation of bauxite.
Of course, the most important thing is that Chinese enterprises still need to continue to play the role of the market, go out, look out, establish companies in various bauxite resources, and protect resources, so as to prevent resources from being monopolized by capital.
On the other hand, there is an obvious shortage of domestic bauxite resources in China, so it is strongly recommended to gradually reduce domestic mining to provide resource guarantee for critical moments; even if mining, it is necessary to give consideration to the allocation and use of low-grade bauxite and high-grade imported ores, so as to better recover and utilize resources, reduce resource damage and prolong the service life of resources.
Reporter: as the downstream industry of bauxite, the production process level of alumina will be the key to the efficient utilization of bauxite. So, how should alumina enterprises make efforts to reduce costs and increase efficiency?
Wen Jinde: I think alumina enterprises can focus on four strategic aspects in order to better achieve efficient utilization, reduce cost and increase efficiency.
The first is to implement the concentrate strategy. In fact, the strategy of concentrate is to reduce the comprehensive cost of the enterprise, including ore logistics cost, production cost, process processing cost, follow-up processing cost, unexpected operation cost and so on. According to statistics, the actual mining cost of imported ore accounts for only 1/4 of the domestic ore mining cost, while the ore cost generally accounts for only 30% to 50% of the alumina manufacturing cost. The unstable operation in enterprise production and the subsequent storage of red mud will also lead to an increase in costs. Therefore, in the process of enterprises from transportation to production, and then to processing, it is necessary to promote the reduction of mineral consumption, logistics costs, production and processing costs, and then to stable operation to achieve loss reduction, and finally achieve comprehensive cost reduction. It is the only way for enterprises to promote efficient utilization.
The second is to implement the energy strategy. The energy cost generally accounts for about 15% of the alumina manufacturing cost, and how to reduce this part of the cost is also a problem that we must consider. First of all, it is necessary to maximize the output in the production process and realize the thermal comprehensive utilization of the process; secondly, we should do everything possible to reduce the cost of thermoelectricity and roasting coal to produce gas; finally, we should constantly improve the level of equipment and management. to achieve continuous cost reduction.
The third is to implement the strategy of auxiliary materials. The consumption of caustic soda and lime accounts for 15%-20% of the cost of aluminum oxidation, which is the main auxiliary material for alumina production. Low alkali and low ash is the main idea of alumina production control at present.
The fourth is to implement the management strategy. Management is the eternal theme of enterprises, and on-site management is the primary aspect of management. We should start with "on-site management" to maintain production order and reduce waste in an all-round way. Secondly, we should spare no effort to promote production management, and the production process should be "intensive cultivation" and reasonable control in accordance with the requirements of lean production. Thirdly, it is necessary to carry out equipment management and intelligent management in a timely manner, so that the equipment is getting newer and newer, and the means of equipment control are constantly improved, so that the equipment can always maintain an advanced and efficient state. Finally, the most important thing that can not be ignored is safety management, we should fully realize that safety is the first, and safety in production is the greatest benefit of the enterprise.
In short, the comprehensive cost control of alumina is a systematic project, and reducing costs and increasing efficiency also need systematic consideration. the four major strategies mentioned above can only be called "bull's nose" strategy. In the production and operation of enterprises, production scale, operating rate, equipment level, production cost, index control and so on are all closely related to cost consumption. therefore, if we want to realize the efficient utilization of resources, we need to implement more strategies. The finer the better, the more refined the better, to jointly respond to the new changes in China's bauxite market and promote the development of China's aluminum industry to high quality.
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