The value of tailings resources can not be ignored electrothermal refining aluminum silicon alloy

According to the bulk non-ferrous net reprint: Not long ago, China Nonferrous Metals newspaper published in the essay "tailing resources: eat dry squeezed net waste into treasure," the last sentence wrote: "The tailings resources in social benefits, ecological benefits are obvious, even if The economic benefits are no less than those of concentrates and imported mines.” This is an easy-to-innovate industry person who has always wanted to be creative, and it is easy to draw conclusions based on information analysis and accounting provided by the essays, but it is difficult to win the trust of general readers. This article continues to add a little supplementary analysis.

The above article focuses on two methods of development and utilization. One is to prepare alumina, active silicon and other valuable components by pre-siliconation treatment of high-silica-alumina, and the second is to electrothermally refine aluminum-silicon-titanium master alloys. According to reports, more than 80% of the alumina produced from domestic diaspore is prepared using the Bayer process. However, due to limited information resources, it is not known how many emissions and stockpiles there are. It can only be inferred from normal knowledge: the amount is not in the minority. The Great Wall Aluminum Corporation is still being used as an example to analyze and determine.

Tailings have potential economic benefits

In the ore dressing tests conducted in the 1990s, Xiaoguan Mine was selected. Raw ore A/S 5.83, Concentrate A/S11, Yield 80%, Tailings A/S1.4; Concentrate alumina recovery rate 86.45%, Impurities mainly 80% of Fe2O3 and TiO2, and others The total content of calcium, magnesium, potassium, and sodium oxide, impurities was 8.83%, and the loss of heat was 13.26%. In recent years, the alumina content of the selected ores decreased, about 60%, A/S3.5, concentrate A/S6.5, tailings A/S1.35, annual processing volume 700,000 tons, output concentrates nearly 50 In tons, the concentrate yield is about 72%. According to the concept of best use, each ton of alumina produced requires about 2.3 tons of ore, and 1.4 tons of concentrate per ton of mineral. If the concentration of alumina in the concentrate is improved by 90%, the ton concentrate is roughly calculated. Can create a production value of 1600 yuan up and down. The tailings, red mud (Bayer process without lime) together, can create a value of 1,700 yuan, because the output is active SiO2, the price is more than twice the alumina. If calculated by weight, the output value of 2,500 yuan per ton of tailings and red mud will be no less than concentrate. As for the imported ore, the average output of one ton of alumina per 3 tons is worth 2,500 yuan, and the price of one ton of iron powder is 900 yuan. If the amount of red mud is more than one ton, it can create a production value of 500 yuan, a total of 3,900 yuan. The average value of production per ton of imported ore is 1,300 yuan, and the relative ratio between the two is even more obvious. Therefore, the essay is not exaggerated, so it is a mystery, but it is rooted and practical. The key to the problem is the way of thinking. For many years, people have seen only alumina, tailings, and red mud worthless. They have long been accustomed to becoming entrenched and deeply entrenched. It is easy to change! It is only hoped that the new normal will stimulate the ecological construction. There can be a turnaround. Once the potential value of the tailings will be discovered one day, it will be worth a hundredfold, and it will be regarded as a fragrant oyster. The development and utilization of the tailings with high value-added and turn waste into treasure will become a reality!

There are experimental studies at home and abroad for pre-silicon removal of high-silica-alumina, and university textbooks also have special chapters. For example, in Chapter 11 of “Light Metallurgy,” published by Metallurgical Publishing House in 1959, Kaolin is used as an example. For detailed discussion, there are reference values.

Electrothermal refining aluminum silicon alloy Mo give up

It is indeed unheard of to mention that refining aluminum-silicon alloys with tailings as the main raw material. This is related to the characteristics of Chinese bauxite. China's dicalite has the characteristics of high silicon and low iron, which is also an advantage. Otherwise, the iron-containing high iron removal processing is difficult, the cost is high, and the output value is low. In the former Soviet Union, the main raw material for the production of Al-Si alloys was selected from Aktasse ore production, precisely because of the low iron content of the mine. After one rough selection and two fine selections, the A/S ratio reached more than 1.2. Pellet material, but the tailings will be abandoned. The United States tried Arkansas high-iron bauxite because it was difficult to remove iron and concentrate iron content did not meet the standards and give up the test. China's bauxite contains low iron content. Even tailings can meet the standard requirements by using high gradient magnetic separation. Due to the small processing difficulty and low cost, the unit cost of refining tons of alloy is 2.8 tons, which is only one or two hundred yuan. This alone is nearly 2,000 less than the former Soviet Union's selection of nearly 2 tons of kaolin and 800 kg of alumina collocation. yuan. The cost of the alloy varies from about 7,000 yuan to 10,000 yuan per ton depending on the electricity price. The selling price is calculated at a market price of 13,000 yuan per ton. A miner's furnace with an annual output of 10,000 tons needs to invest 150 million yuan. With the use of an idle heat furnace, it needs to invest 40 million yuan. The tailings contain a small amount of titanium oxide, and the resulting master alloy contains titanium, and a small amount of titanium can optimize the mechanical properties of the alloy. Since the master alloy can be used to formulate hypoeutectic deformation alloys in addition to aluminum-silicon casting alloys, the application scope and market space can be expanded. Especially in the processing of aluminum scrap, it can effectively resolve some difficulties that have been formed for a long time. To promote the transformation and upgrading of enterprises as soon as possible and embark on a healthy development.

However, contrary to expectations, in the 1950s, Fushun Aluminum Plant and Tangshan Steel Plant and other large-scale iron alloy factories invariably conducted electrothermal refining of aluminum-silicon alloys. There was no success. Since then, two large companies have established projects on behalf of aluminum-silicon alloys, built large-capacity submerged arc furnaces, and tried to refine aluminum-silicon alloys. They also ended up with no results. They only had to transfer ferro-alloys. In recent years, they could only be helpless in the laboratory. In the small-scale experiment of aluminum-silicon alloy industrialization, China's aluminum industry has no way to face the electrothermal refining of aluminum-silicon alloys, and has been discouraged. Electrothermal refining of aluminum-silicon alloys has entered the hibernation period.