First, the basic concept of poor ore resources
Lean ore, also known as low grade ore, is relative to high grade ore. What kind of sample position mine is considered to be a poor ore, for which there is no uniform classification standard in the world. Even in the same country and in the same region, there is no absolute standard for the division of poor ore. In fact, the determination of a country's poor and rich grade standards depends mainly on the status of mineral resources and the level of mining, selection and metallurgy. Lean ore is both a technical concept and an economic concept. In terms of technology, the poor ore refers to the mineral resources that are not mature enough due to the low grade of ore and the current mining, selection and smelting technology. In economic terms, poor ore can be understood as a low grade of ore, leading to the development and utilization of mineral resources with poor economic returns.
What kind of economic benefits are considered to be poor economic benefits? This is also a relative economic concept. The so-called poor economic performance, refers to the development and utilization of mineral resources, mining and poor profitability in the economy, not up to the industry benchmark rate of return, or of long-term lending rates of commercial banks can not. At present, the 5-year long-term loan interest rate of China's commercial banks is about 5% to 6%. In other words, we can make the profit level after development and utilization is not high, and the mineral resources with a profit rate of generally 6% to 8% or less are regarded as poor ore.
China's mineral industry requirements reference manual stipulates that the general industrial requirements for lead ore deposits are: the cut-off grade of sulfide ore is 0.3% to 0.5%, the lowest industrial grade is 0.7% to 1.0%; the cut-off grade of oxidized ore is 0.5% to 1%. The minimum industrial grade is 1.5% to 2%; the boundary grade of mixed ore is 0.5% to 0.7%, and the lowest industrial grade is 1% to 1.5%; the general industrial requirement for zinc deposits is: the boundary grade of sulfide ore is 0.5% to 1%. %, the lowest industrial grade is 1% to 2%; the cut-off grade of oxidized ore is 1.5% to 2%, the lowest industrial grade is 3% to 6%; the boundary grade of mixed ore is 0.8% to 1.5%, and the lowest industrial grade is 2%. ~3%.
According to a survey conducted by the Ministry of Land and Resources in 2001, at the time of production lead mines in China, the lowest grade is 0.3%, the highest is 3%, with an average of 0.82%, while the 0.5% mine has the most, accounting for 43.75%. The actual minimum industrial grade, the lowest is 0.5%, the highest is 4%, the average is 1.39%, and the most between 0.7% and 1% of the mines, accounting for 47.27%; in the production of zinc mines, the lowest grade is 0.2%, the highest is 3%, the average is 0.66%, and the most between 0.2% and 0.5% of the mines, accounting for 87.5%; the actual minimum industrial grade, the lowest mine is 0.7%, the highest mine is 18%, the average It is 2.95%, while the actual lowest industrial grade is between 1% and 3%, accounting for 73.17%.
According to this survey, we have reason to grade the lead in the lead deposit between 0.3% and 2%, and the zinc in the zinc deposit is between 0.2% and 3%. In the lead-zinc deposit, the sum of the lead and zinc grades is Resources above 0.5%, but generally not higher than 6%, are collectively referred to as lean ore resources. If we consider the specific situation of the sharp increase in the price of lead and zinc in recent years, the upper and lower limits of the grades of lead and zinc lean resources can actually be reduced appropriately.
    Second, the number of lead and zinc poor ore resources in China
The main characteristics of many important large-scale mineral resources in China are that there are many poor ore, difficult to mine , and few rich ore, which has a very important impact on the development and utilization of China's mineral resources. Of iron ore reserves, 98.1% of the total reserves depleted iron, copper ore, bauxite, manganese ore, phosphate ore, pyrite, and even lead-zinc is also the case. One of the important reasons for the unutilized mineral deposits in China's large minerals is the low grade of ore.
The resource characteristics and development and utilization conditions of lead-zinc mines in China are: large and medium-sized mines and small extra-large mines. Among the discovered mineral deposits, the reserves of lead and zinc in large and medium-sized deposits are 72% and 88%, respectively; There is more lead and less zinc in the ore, the lead-zinc ratio is about 1:2.6, while the foreign is 1:1.2; the lean ore is rich, the rich ore is less, and the choice is easy. The sum of the lead and zinc grades in the mine is between 5% and 10%, which is greater than 10% grade ore only accounts for 15% of the total reserves, while foreign mines are generally high in grade, lead and zinc are mostly above 10%; sulfide ore is the majority, 90% of reserves are primary sulfide ore, only Yunnan Lanping, Huize, Guangxi's dome, Liaoning's Zihe and Shaanxi's Leading Mountain and other small lead-zinc deposits. The type of ore is complex, with a single type of lead or zinc ore, a large number of associated components, and more than 50 useful elements associated with it, mainly gold , silver, copper, tin , cadmium , sulfur, fluorite and rare dispersing elements. . Mainly zinc ore type of the ore, copper ore lead zinc, tin ore, lead ore, antimony, lead, zinc, tin and antimony ore, zinc, copper ore and the like.
According to the results of the reserves reform conducted by the Ministry of Land and Resources in 1998, as of the end of 1999, 982,290 tons of lead ore resources were marginalized, accounting for 3.22%, and 2,635,500 tons were sub-marginal economies, accounting for 8.62%. There are 429,300 tons of zinc mines in the marginal economy, accounting for 0.50%, and 5.971 million tons is the marginal economy, accounting for 6.92%; the marginal economy plus the submarine economy, the sum of the two, that is, about 365 The 10,000 tons of lead ore resources and 5.5 million tons of metal zinc ore resources can be clearly classified as low grade ore, which account for 12% and 7.5% of lead and zinc reserves, respectively.
In fact, the number of low-grade ore deposits in China's lead and zinc reserves is far more than that. According to the results of the reform of reserves, as of the end of 1999, there were 1,756.51 million tons of lead resources in China, accounting for 57.46%; among the zinc resources, there were 4,776,500 tons of intrinsic economy, accounting for 56.98%.
There are many reasons for the reason why this part of lead and zinc resources is classified into the intrinsic economy when the reserves are changed. However, the main reason is that the degree of exploration is low, and it is still in the stage of census or evaluation. At that time, it was not necessary to carry out technical and economic evaluation. Second, the state-owned mineral deposits have low grade and high development cost. The state considered that it was not worth or temporarily worth developing, so there was no Including it in the development plan, of course, there is no technical economic evaluation of the deposit. In the first case, if the grade is high and there is obvious development and utilization value, then after several years of work, its economy should have been determined; in the second case, the vast majority of relevant resources should It belongs to low-grade mines with low economic utilization value, although people have not made economic evaluations for them.
Objectively speaking, China's lead and zinc mineral resources are originally rich in rich ore, less rich in minerals, after years of intensive mining, especially after selective development since the 1980s, high grade, high economic value of lead Zinc deposits have basically been developed, or have been included in the national development plan. As a complete deposit, there is not much left in development value. This is the overall evaluation of China's lead and zinc mineral resources in the late 1990s. Although this conclusion is biased, it also illustrates the fact that most of the lead and zinc resources in China are low-grade ore. According to various aspects, at least 60% of China's lead and zinc resources are classified as low-grade ore.
At the end of 2005, among the identified reserves of lead and zinc mines in China, 25.41 million tons of lead and 52.26 million tons of zinc were resources. If 60% of them are low-grade ore, then at least 15 million tons of lead are estimated. 30 million tons of zinc belong to low grade ore.
In practice, lead and zinc production mines typically use 4% as the lower limit for lead-zinc ore mining.
    III. Current Status and Problems of Utilization of Lead and Zinc Lean Resources in China
After decades of unremitting efforts, China's lean ore utilization has also achieved some achievements, and has made breakthroughs in some aspects. It has invented a number of mining scientific and technological achievements that have achieved significant international advanced levels, such as super heavy oil and Special heavy oil mining technology, development and utilization of low-grade iron ore magnetic agglomeration re-election technology, and timely promotion, technology into productivity, and achieved great economic benefits. At the same time, China has also vigorously introduced advanced mining and metallurgy technology, which has played a major role in the development and utilization of China's copper, gold and uranium minerals.
There are mainly five industrial types of lead-zinc ore in China. The first is the skarn type lead-zinc deposit, which is one of the important types of lead-zinc deposits. It has the commonality of skarn type deposits: the grade of lead and zinc in the ore is high, and it is accompanied by metals for comprehensive utilization, such as copper, silver, and various rare and rare elements, mainly bismuth , indium and cadmium. Such deposits are widely distributed, but their scale and occurrence vary greatly. Second, hydrothermal vein-like lead and zinc deposits are produced in structural fractures of various rocks. The ore-forming is mainly filled, and the ore body is vein-like. The body grade is high and widely distributed, but the size of the deposit varies greatly. Such as Hunan Taolin, Liaoning Qingchengzi and other lead-zinc deposits. More than half of China's lead ore production is provided by this type of deposit; the third is the pyrite-type lead-zinc deposit, which has the same characteristics as the copper-bearing pyrite deposit, but contains more lead and zinc. There are such types of ore in the northwestern part of China, such as Xiaotieshan. Pyrite is the main mineral for comprehensive utilization, followed by gold and silver. The fourth is the hydrothermal metasomatic lead-zinc deposit in carbonate rock. Mainly. The composition of ore is mainly galena and sphalerite, and associated minerals such as quartz , calcite , fluorite and barite are available for comprehensive recycling. The ore is mainly dense and has a rich lead and zinc content. Elements associated with ore such as silver and rare elements such as cadmium, antimony and indium are available for comprehensive utilization. The Huangshaping lead-zinc deposit in Hunan belongs to this type of deposit; the fifth is the layered lead-zinc deposit in the carbonate layer, which is produced in limestone and dolomite . The ore bodies are mostly layered, and the mineralization phenomenon is generally disseminated. The mineral composition of ore mainly includes galena, sphalerite, and sometimes chalcopyrite; the gangue mineral is mainly calcite. The content of lead and zinc in ore is not high, but the size of the deposit is often large.
The recovery rate of lead-zinc mines in China is generally relatively high. According to a survey we conducted in 2004, the average recovery rate was 92.62%. The mining is mainly pit mining, the output accounts for 89.27% ​​of the total output; the average grade of mining is 3.69% lead, 5.77% zinc; the mining recovery rate is 92.01%; the mining output only accounts for 10.73% of the total output, and the average grade of mining is lead 1.98. %, zinc 9.26%, mining recovery rate of 97.68%.
However, there are still some mines. Due to various reasons, some low-grade lead-zinc ore or oxidized ore resources have not been produced in the production mines, or they have been produced but not yet utilized.
According to a survey commissioned by the National Development and Reform Commission in 2004, there are still a large number of low-grade and refractory ores in China's lead-zinc production mines. For example, Jiangtong Group's Yinshan Mine currently has 300. The 10,000-ton low-grade lead-zinc mine has not yet been recovered. The Baiyin Company's dam-lead-zinc mine still has a large amount of ore with less than 4% lead and zinc grades. The Shuikoushan Kangjiawan Mine in Hunan also has 320,000 tons of low-grade lead and zinc. The mine has not been utilized, and the Qixiashan lead-zinc mine in Nanjing has 1.9 million tons of refractory oxidized ore that has not been utilized (some are still under the scenic area). Yunnan Huizechihong lead-zinc mine has a reserve of 5%. 650,000 tons of refractory oxidized ore were not used.
Complex of zinc ore type, up to a total of 50 kinds of associated components, which are mainly of copper, silver, gold, tin, antimony, cadmium, bismuth, gallium, indium, germanium, mercury, sulfur, fluorite and the like dispersed elements It has great comprehensive utilization value and also adds certain difficulty to China's smelting production. The most important associated elemental silver, its reserves account for 60% of the total reserves of the country's silver mines. Currently, the total and associated silver production from lead-zinc mines accounts for 70% to 80% of the national silver production. The lead-zinc ore symbiotic components Cu, S, Sn, Bi, Mo, CaF 2, etc., can separate the separate concentrate products during the beneficiation process, while other elements generally enter the lead or zinc concentrate during the beneficiation, in the smelting Process recycling.
Different co-concomitant components require different separation methods. For example, copper generally obtains qualified copper concentrate by copper-lead separation during flotation; tin sulphide needs to be recycled by heavy-floating combined process; bismuth recovery uses flotation to obtain lead bismuth concentrate, and further smelting It is recycled; the main carrier minerals of gold in lead-zinc mines are copper minerals and pyrite. The recovery of gold is recovered at the same time as the recovery of the main carrier minerals; the recovery of the main sulfur mineral-pyrite is relatively simple, generally Large and medium-sized enterprises have a flotation process for recovering pyrite. Antimony, selenium , cadmium and indium are generally recovered in smelting. For example, cadmium and selenium in the ore of Xiaotieshan Mine are enriched in copper concentrate and lead-zinc concentrate by flotation, and are recovered in smelting. Indium in Dachang Mine is enriched in zinc concentrate by flotation, and then recovered in smelting. The strontium in the Huize lead-zinc mine in Yunnan is also recovered by flotation and is recovered in smelting.
In general, the recovery of resources during the beneficiation process is not ideal: the average grade of ore is 3.46% for lead and 5.89% for zinc; the concentrate grade is 64.35% for lead concentrate and 50.57% for zinc concentrate; The lead ratio was 86.71% and the zinc was 87.05%.
The recovery rate of some main products of mines is not high. For example, the recovery rate of lead in the lead-zinc ore dressing plant is only 68.35%, the recovery rate of zinc is only 85.61%, and the lead-zinc grade in tailings is 0.29. % and 0.94%; the recovery rates of lead, zinc and silver in Yunnan lead-lead ore dressing plant are only 75.26%, 72.22% and 62.61%, respectively, while the lead, zinc and silver grades in tailings are 0.98% and 0.43% respectively. 52.59g/t; the recovery rate of lead and zinc in Yongchang lead-zinc ore dressing plant is only 84.78% and 82.63%, respectively, while the lead and zinc grades in tailings are as high as 0.5% and 1.2% respectively; the tail of Huizexuhong lead-zinc mine The lead and zinc grades in the mines are as high as 0.93% and 1.15% respectively; the lead-zinc ore dressing recovery rate is not high, and the main reason for the high grade of tailings is that the proportion of oxidized ore is higher, which is higher than the data presented in the exploration report. However, the current process of the plant is obviously not suitable for the selection of ore with a higher oxidation rate. Obviously, the process of selecting such a high-oxidation lead-zinc ore dressing plant should be adjusted according to the actual conditions of the ore.
Judging from the actual situation of the investigation, the comprehensive utilization of most of the lead and zinc mine resources in China has been carried out, but the development is not balanced. The results of several surveys indicate that the recovery rate of associated silver in lead-zinc mines is relatively high, ranging from 58% to 75%, and the recovery rate of associated silver and associated gold is over 95%. However, the depth and breadth of scientific research work for comprehensive utilization of resources is insufficient. The comprehensive recycling of resources by most mines has not yet formed a systematic scientific management system, and there is a lack of comprehensive utilization research from mineral raw materials to processing and utilization.
The content of valuable elements in lead-zinc mine tailings is generally high. The national average grade is lead 0.25% and zinc 0.64%, both exceeding the boundary grade of lead-zinc deposits. Mainly associated with copper, silver, gold, tin, antimony, cadmium, antimony, gallium, indium, antimony, mercury, sulfur, fluorite and dispersing elements, etc., with great comprehensive utilization value, so the technical and economic conditions from resource utilization In terms of aspect, most of these lead-zinc tailings are artificial low-grade ore as long as there are appropriate fiscal and tax incentives.
In fact, at present, China has basically possessed the technical conditions for utilizing lead and zinc lean resources. Scientific research institutions have increased the introduction, digestion, absorption, imitation and innovation of foreign advanced technology and equipment, and formed a set of high-efficiency lead and zinc smelting technology. For example, in high-efficiency grinding technology and equipment, semi- autogenous grinding machine replaces medium and fine crushing operations. The screening operation and the ore operation link shorten the process, reduce the dust generation point, and are more conducive to the stability of the subsequent operation; the application of the large flotation column in the large-scale high-efficiency flotation equipment makes the grade low and the inlay size fine. The effective use of refractory mines with complex mineral composition is possible; in the solid-liquid separation equipment, the industrial application of high-efficiency thickeners is becoming more and more common, ceramic filters are replacing vacuum filter-type filters, and the former has the advantage of being ingenious. The capillary phenomenon is utilized, and the original cloth filter bag is replaced by the microporous ceramic filter medium, thereby further reducing the water content of the filter cake, making the filtrate clearer, prolonging the life of the filter medium ceramic plate and reducing the power consumption.
In the aspect of high-efficiency flotation process technology, a series of novel flotation process structures have been developed, such as flotation flotation, branch cascade flotation, asynchronous hybrid flotation, partial fast-priority flotation, etc., for Yunnan Huize lead-zinc mine. Deep high-grade rich lead-zinc mixed ore, research success "first sulfur after oxygen - lead after zinc - etc. floatable - asynchronous lead - with sulfur asynchronous mixing - lead sulfide, zinc, pyrite separation - lead oxide Sulfuration flotation-Zinc oxide non-desilting flotation of complex polymetallic sulfide ore-oxidation mixed ore comprehensive beneficiation new technology" has been successfully used in the construction of a new 650,000 tons / year of concentrator. In the aspect of potential regulation and electrochemical control flotation, under the leadership of Academician Wang Xianzuo, he has reached the international leading level in the theoretical research of sulfide ore flotation electrochemical and potential-controlled flotation, and has also made breakthroughs in practical applications. The new technology has been applied in several lead and zinc concentrating plants such as Fankou Lead-Zinc Mine. Practice has proved that it has obvious advantages such as advanced technology, simple process, less dosage of chemicals, high sorting index and less environmental pollution. It is a major innovation at home and abroad and has made significant contributions to the development of flotation theory. This achievement won the first prize of National Science and Technology in 2000. In the field of potential regulation and electrochemical control flotation, Beijing Research Institute of Mining and Metallurgy has also carried out a series of researches on the research and development and process control of potential electrodes and sensor technology for potential measurement and control: in 1994, the control of slurry in Xilin lead-zinc mine The potential and application of the distributed system to achieve the optimization control of 14 kinds of medicines in the lead-zinc ore flotation process was successful, and won the second prize of the National Science and Technology in 1996. In the initial flotation expansion test of Xinjiang Ashele copper-zinc ore, the use of dedicated potential sensors to implement online potential-controlled flotation was successful. The use of special sensors in the Wulayu gold mine to determine the slurry potential to achieve the identification of sulfide ore and oxidized ore types and automatic switching of the pharmaceutical system, the gold recovery rate increased by 2.6 percentage points. In the flotation of lead-zinc ore, we know that lead oxide ore is generally applied to the flotation of xanthate, and zinc oxide ore is generally applied by the method of flotation of ammonium sulfide. In recent years, foreign countries have developed process technologies such as modified amine flotation and mixed collector flotation. The domestic Beijing Research Institute of Mining and Metallurgy also has unique process technology in this respect.
About pre-selection tailing and tailings re-election. The application of tailing technology can significantly improve the economic benefits of low-grade lead-zinc ore dressing plants. For low-grade lead-zinc ore (including sulfide ore or oxidized ore) suitable for ore embedding, heavy medium tailing technology can be used to improve the selected grade and improve the economic efficiency of the concentrator. The application of tailings re-election has produced very good economic benefits. Since last year, the high price of lead and zinc has stimulated the enthusiasm of many enterprises and individuals to engage in the re-election of old tailings, and achieved results. For example, the Yindongpo Gold Mine in Henan Province has been economically good for many years in the recovery of old tailings. The effect of flotation of the leaching slag to recover valuable elements is also significant. It is still in the Yindongpo gold mine in Henan, and a gold mine in Qingdao, etc., recovering lead, zinc, gold and silver from cyanide leaching residue, and has achieved good results. For example, the leaching slag flotation plant of Zhuzhou Smelter has been successfully operated for many years and has achieved good economic benefits.
The application of tail-splitting technology is beneficial to enhance the recovery of low-grade associated elements. In the 1999 mine survey, the comprehensive recovery of lead-zinc mines was not optimistic. In particular, the comprehensive recycling of small private lead-zinc mines is relatively poor. Since 2005, this situation has changed, but some companies still lack the technology in this area. I believe that on the one hand, some of our companies have patronized the production of buried products, and have lacked foresight in applying new technologies and new methods to solve the problems in production. On the other hand, they have also weakened the application of relevant technologies with relevant government departments and mastered these applicable technologies. The experts are not enough to go out and promote new technologies and methods.
It is worth noting that lead-zinc ore is often accompanied by a large amount of silver, gold and other valuable elements such as antimony, cadmium, indium, etc., as well as by-products of sulfur concentrate. The value of these by-product minerals tends to be relatively high, and some even exceed the main production. In this regard, we should give high priority to all of us here, especially corporate decision makers.
Key technologies to enhance the recovery of low-grade associated elements: First, to find out the basic properties, embedding conditions and possible carriers of low-grade associated elements, to provide a basis for efficient recycling technology; second, in order to improve the recovery of precious metals, generally cannot Flotation in a high alkali medium. Third, the application of suitable high-efficiency selective collectors is one of the key technologies for improving low-grade associated elements. Fourth, researching and developing a suitable process structure based on the nature of the ore and possible combinations of agents is the key to improving overall metal recovery.
In the recovery of low-grade associated elements, Yunnan Huize Lead-Zinc Mine, Fankou Lead-Zinc Mine, Western Mining, Nanjing Qixiashan Lead-Zinc Mine are typical. The Qixiashan lead-zinc mine and the mineral recovery rate of the associated silver in the ore, together with the Beijing Research Institute of Mining and Metallurgy, jointly research and develop a new beneficiation process for improving the recovery rate of lead and silver, and carry out the original mineral phase and process on the company's lead-zinc ore. Based on the mineralogical research and a large number of beneficiation tests, the best separation fineness, flotation pH potential and ratio of the drug were determined. In February 2006, the industrial application of the new process began. Compared with the pre-application 2005, the recovery rate of lead and silver ore was increased by 12.93 percentage points, the zinc recovery rate was increased by 0.67 percentage points, and the lead metal recovery rate was increased by 4 percentage points. The annual sales income increased by 25.528 million yuan, and the annual profit and tax increased by 24.53 million yuan. The economic benefits are very prominent. This year, the silver recovery rate has been improved by more than 10%.
Application of the combined technology of fine metallurgy for medium and low grade lead oxide zinc ore resources. In China's Yunnan and Guizhou regions, there are abundant lead-zinc ore resources. Since the high-grade ore has been developed less and less for many years, a large number of medium- and low-grade lead-zinc ore resources are economically and rationally developed. The agenda of the decision-making level. At present, a better technical route in this respect is to adopt a technical solution for joint processing of metallurgical and metallurgical processes. That is to say: the ore dressing adopts the technical scheme of positive and negative flotation, and produces the lead-zinc concentrate which is required by the joint technology of the smelting and smelting, but it is not necessarily the high-grade lead-zinc concentrate which is required by the national standard; the metallurgy can be immersed and purified by using sulfuric acid. A series of processes produce metals. The technology of this area of ​​Beijing Mining and Metallurgy Research Institute is also constantly researching and improving. In fact, there are many direct acid leaching processes in Yunnan, and many rich people have been created under the current high price conditions. However, the large-scale application of the acid leaching process must pay attention to protecting the ecological environment.
To sum up, there are four main problems in China's use of lean ore including lead and zinc.
First, a policy system that encourages the use of poor ore at the national level has not yet been formed.
Second, the use of new technologies to develop and utilize lean ore is not large.
Third, the cost is not completely reasonable. It is still difficult for most companies to accept. However, after the price of lead and zinc has risen, this is no longer a problem.
Fourth, the level of technology has to be improved compared with foreign countries.
    4. The experience of foreign experience in using poor ore resources to us
(1) Human development and utilization of mineral resources must follow the law from rich to poor
Practice has shown that the development and utilization of mineral resources by human society always begins with rich mines. With the advancement of society, the growth of demand for mineral resources, the improvement of economic and technological level, and the gradual depletion of high-grade mineral resources, the direction of development and utilization has gradually shifted to low-grade lean ore, which has gradually reduced the mining grade of ore.
In foreign countries, as a large-scale mineral resource, the mining grade of lead-zinc ore is the same as that of non-ferrous metals such as copper. According to reports, during the 30 years from 1950 to 1980, in the important polymetallic mining areas of Australia, Canada, the United States, Mexico and other countries, the average ore grade of lead decreased from 3% to 5% to 1.5% to 2.0%, and zinc was from 8 to 8. %~10% is reduced to 4%~6%.
(2) Fully exploiting and utilizing the resources of poor ore is one of the important guarantees for the safety of mineral supply in various countries.
To solve the shortage of domestic resources, there are two ways: one is to use foreign resources, and the other is to make full use of domestic poor ore. Making full use of the country's rich and poor resources has become an important strategic measure for many countries to get rid of the heavy dependence of foreign mines.
However, in our country, the opposite situation has occurred. According to the annual report on mineral resources compiled and published by the Information Center of the Ministry of Land and Resources, the average grades of lead and zinc in 1992 were 2.39% and 4.46%, respectively, which is not much different from that of foreign developed countries. After the implementation of market economy, China The average ore grade of non-ferrous metal mining enterprises showed an obvious upward trend: the average ore grades of lead and zinc in 2000 were 2.81% and 5.58%, respectively, up 17.6% and 25.1% from 1992; They reached 3.41% and 5.89% respectively, up 42.7% and 32.1% respectively from 1992. Under the market economy, the production activities of enterprises are centered on economic benefits. The lack of government supervision, especially the lack of strong fiscal and tax incentives, is the main reason for the rising grade of lead and zinc in China's non-ferrous metal mines.
(3) The government attaches importance to the development and utilization of poor mine security
Due to the disadvantages of resource conditions and the technical level, the cost of developing and utilizing poor ore resources is relatively high. If there is no special policy, enterprises are often reluctant to get involved. Many national governments, especially economically developed countries, often formulate preferential policies to encourage the development and utilization of domestic poor ore resources from the perspective of national interests and resource supply security.
For example, in order to make full use of the poor ore resources such as the accumulated iron ore mines in the Great Lakes region of the country, and to ensure the safety of strategic materials such as iron ore, the US government has taken a number of measures in the past few decades. Shortly after the end of World War II, the President of the United States submitted a passionate request to Congress to request a special bill, the Defense Production Act, to ensure that low-grade iron ore rock ore was put into use. According to the National Defense Production Act, which came into effect in 1950, the government added four new powers in mine production: first, granting loans and guaranteeing loans; second, buying raw materials and establishing reserves; third, in private mines. And plant installation equipment; fourth, allowing mining and manufacturing capital investment to accelerate depreciation. The fourth point is that the implementation of the accelerated depreciation policy is most welcomed by mining companies. It is actually a new tax cut. Another policy proposed by the US federal government to maintain a stable supply of strategic mineral products is to add a section on “Emergency Facility Marketing” in the Internal Revenue Ordinance to replace the need to spend 20 years on nuclear infrastructure. The system of sales allows for a period of five years to write off the main part of a specially licensed capital investment.
Although both bills were enacted during the Korean War, they were not cancelled after the war, but they have been used up to now. The long-term implementation of these two policies in the United States has greatly stimulated the enthusiasm of mining production enterprises to adopt new technologies and upgrade old equipment. Labor productivity has been continuously improved, production costs have been declining, and more lean and mineral resources have been fully utilized.
The South African government also provides preferential policies for gold projects in various aspects such as taxation and subsidies; in particular, it is responsible for the loss of mines and marginal profit mines arising from problems such as the decline in grades, in order to extend the life of the mines.
The Canadian government also attaches great importance to using fiscal and tax incentives to encourage companies to develop low-grade resources in their own countries. For example, as early as the middle of the last century, oil sands and heavy oils were developed. The current technology for producing oil from this unconventional petroleum resource has matured, and the government’s policy preferences have made Canada’s oil production and oil reserves. It has greatly increased and has become a major oil producer in the world.
(4) Developing advanced mining technologies is fundamental to the use of poor ore resources
In recent decades, although the mining resources of many countries in the world have gradually declined, the output of commercial mines has been continuously improved, ensuring the development of the world economy. This should be attributed to the continuous development and innovation of mining and metallurgy technology. Especially in the past 20 years, many major mining, selection and smelting technologies have provided technical guarantees for the development of lower-grade lean ore resources on a larger scale. It can be said that without advanced and applicable mining technology, there can be no major breakthrough in the use of lean ore. These techniques include MINING modern technology, solvent extraction - electrowinning copper technology (SX-EW), gold heap leaching technology, leaching (leachable) uranium mining technology, low-grade chromite technology smelt, and the like.
The experience and lessons of both positive and negative aspects fully demonstrate that in the issue of saving and rational use of resources, there is no government's strong and effective preferential policies for fiscal and taxation, and effective resource policies, relying solely on administrative management of enterprises. Constraint, it is difficult to get twice the result with half the effort.
    V. Countermeasures and safeguard measures for the utilization of poor ore resources in China
Increasing the development and utilization of poor ore resources will expand China's mineral resources base, promote the development of mining circular economy, and finally ease the constraints of economic and social construction on resources. To this end, we must actively explore new systems and mechanisms for resource conservation, intensive development and utilization under market economy conditions. It is recommended to establish a relevant coordinating agency for the utilization of national lean ore resources, and establish a special fund for scientific and technological research on the use of poor ore resources, to support the introduction, development and promotion of major technologies for the use of poor ore; to establish a special plan for the utilization of poor ore resources, with a focus on supporting a batch of Demonstration project for the use of lean ore; carry out the necessary technical and economic evaluation of the proven mineral ore resources. At the same time, we will implement preferential policies and measures to encourage the development and utilization of poor ore resources as soon as possible, study and explore new systems for investment and financing that utilize lean ore resources, new mechanisms for operation and management, and related economic policies, and ensure the large-scale utilization of poor ore resources. .
(1) Establish a special coordination mechanism for the utilization of poor ore resources, and establish a special plan for the utilization of low-grade mineral resources.
It is recommended that the Ministry of Land and Resources set up a special coordination mechanism for the utilization of poor ore resources, and coordinate with the National Development and Reform Commission, the Ministry of Finance and other relevant departments on resources, technology, policies, and investment to form an overall pattern of utilization of low-grade mineral resources. It is recommended that the state set up a special project to carry out the necessary technical and economic evaluation of the proven large mineral ore resources, and establish a special plan for the utilization of low-grade mineral resources to promote the exploration, development and utilization of lean mineral resources, and the introduction and promotion of technology.
(2) Improve laws and regulations on the development and utilization of poor ore resources
In the revision of the "Mineral Resources Law", it is further clarified that the development and utilization of lean ore resources should be required, research and development of laws and regulations to guide the utilization of poor ore resources, and the rational use of poor and scarce resources through laws and regulations.
(3) Do a good job in mineral resources planning and formulate resource policies that are conducive to the use of poor ore
In the overall planning of mineral resources, through the establishment of a unified, coordinated, functionally coordinated mineral resource planning system, the concept of circular economy, conservation and rational use of resources is established, and mine enterprises are clearly required to make full use of poor ore resources and to make lean resources. The use of this is included in the system of the National Circular Economy Law. Promote the development of circular economy in the field of mineral resources by implementing a special plan for the utilization of poor ore resources. The implementation of the Catalogue of Comprehensive Utilization of Resources will enable Dali enterprises that use lean ore resources to fully enjoy the preferential policies for comprehensive utilization of the state.
(4) Revising and improving the mineral resources utilization index system
Revise the existing industrial indicators of mineral resources, reduce the industrial grade and the cut-off grade to a reasonable range, and use as much of the poor ore resources as possible. Exploration, evaluation and development of the use of poor ore resources according to technically feasible and economically reasonable requirements.
(5) Improving the incentive mechanism for the utilization of poor ore resources
Increase support for pilot demonstration projects for the utilization of low-grade mineral resources. Support mining enterprises to develop poor ore resources through measures such as tax reduction, financial support, price adjustment, and technology promotion. Establish a normal resource protection and resource for the exploitation of mineral resources in the mineral resources compensation fees collected by the state. Secondly, the competent national authorities should make a clear numerical definition of “low grade ore” according to the current resource situation and economic situation; reduce or exempt income tax on the income of mining enterprises using low grade ore or tailings treatment. Resource tax and resource compensation fees. In order to reduce the interference of local government interests and ensure the implementation of this policy, it is recommended that the management of taxation and fees for large typical backbone mines be centralized to the competent authorities of land and resources at or above the provincial level to encourage and stimulate mining enterprises to be economically and technically permitted. Maximize the recovery of mineral resources.

High Qualtiy, High cutting Performance, High Precision CNC Wire Cutting EDM Machine. China leading manufacturers and suppliers of CNC Wire Cut EDM Machine, EDM Machine , and we are specialize in Wire Cutting EDM Machine, etc.

wire cutting edm machine

CNC Wire Cut EDM Machine

CNC Wire Cut EDM Machine,EDM Machine,Wire Cutting EDM Machine,CNC Wire Cut

Suzhou Simos CNC Technology Co., Ltd. , http://www.edm-machines.com