Sulfuric acid slag refers to the pyrite slag (also known as pyrite slag) produced in the sulfuric acid production process, which is one of the main solid wastes produced by the chemical industry. For every ton of sulfuric acid produced, 0.8-1.5 tons of sulfuric acid slag will be discharged, accounting for 1/3 of chemical waste. Sulfuric acid slag is a very valuable secondary resource. If pyrite slag can be utilized, the shortage of iron ore supply can be greatly alleviated. Moreover, the price of iron has risen in the past two years, and the comprehensive utilization of pyrite slag can not only protect the environment, but also avoid the waste of resources, and can also win profits for enterprises. What are the ways to use sulfuric acid slag? As a manufacturer of sulfuric acid slag grinding equipment, Guilin Hongcheng will introduce you in detail today.
Utilization method of sulfuric acid slag: as building materials
1. Using sulfuric acid slag to make bricks: Due to the low content of active substances such as silica and alumina in sulfuric acid slag, a small amount of cinder and coal ash must be added, and lime is used as the cementitious material. Sulfuric acid slag is mixed with ingredients, wheel milled, Finished bricks are produced through pressure molding, steam curing and other processes. The use of sulfuric acid slag can not only produce ordinary wall bricks, but also can prepare colored wall bricks and glazed bricks.
2. Using sulfuric acid slag to make cement flux: the use of sulfuric acid slag as cement flux can not only correct the composition of Portland cement raw material mixture, increase the content of iron oxide, reduce the modulus value of alumina, but also increase Strengthen the strength of cement, enhance the corrosion resistance of mineral water, and reduce its thermal bending phenomenon. In addition, the firing temperature can also be reduced, which is beneficial to reducing heat consumption and prolonging the service life of the refractory bricks of the firing furnace. Cement production does not have strict requirements on the quality of sulfuric acid slag, and it can be used if it contains 30% iron. The use of sulfuric acid slag instead of iron ore powder as a flux for cement firing is a direction of its comprehensive utilization, especially suitable for low iron content or sulfur, arsenic. Such as sulfuric acid slag treatment with more impurities.
Utilization method of sulfuric acid slag 2: extracting valuable metals
In order to avoid the pollution of sulfuric acid slag to the environment, use sulfuric acid slag as raw material, add active reducing agent (C6H1206), use waste sulfuric acid to directly reduce and leach iron and produce iron yellow, and then use P204 (di-2 ethyl phosphoric acid) as the main body The ternary extractant extracts and recovers the copper in the leaching solution, and extracts gold and silver from the leaching slag by using the whole mud cyanidation and zinc powder replacement process, which economically and effectively recycles the valuable metals in the slag, such as iron, copper and The recoveries of gold reached 93.31%, 80.78% and 90.18%, respectively.
Utilization method of sulfuric acid slag three: preparation of iron products
1. Utilization of sulfuric acid slag to recover iron: The method of preparing iron concentrate from sulfuric acid slag is the most widely used method of beneficiation and has achieved remarkable results. Common processes include: magnetization roasting-magnetic separation, gravity separation, gravity separation-magnetic separation, gravity separation-flotation and other combined processes.
2. Utilization of sulfuric acid slag to prepare ferrous sulfate: pyrite slag is used to prepare ferrous sulfate. The main processes include sulfuric acid direct acid leaching reduction method and high temperature reduction method. The advantage of the high-temperature reduction method is that the recovery rate of iron in the slag is high, but the disadvantage is that the reaction temperature is as high as 800 "C, the energy consumption of the reaction process is large, and the equipment is expensive; in the process of the direct acid leaching reduction method, the reaction temperature is low and the energy consumption is small. , but the recovery rate of iron in slag is low.
3. Utilization of sulfuric acid slag to prepare iron red, iron yellow, and iron black: The methods of producing iron red with sulfuric acid slag mainly include dry method and iron yellow calcination method. The dry method is to wash, dry and pulverize the Fe2O3 obtained by calcining the vitriol (FeSO4•7H2O) prepared from the slag to obtain the iron red product. Iron red can also be prepared by the dry method of slag by using the principle of reverse flotation, adding ether amine and xanthate to remove silicon and desulfurization, and then leaching and removing impurities with alkali leaching ammonium salt, then oxidizing and roasting at 600~700°C, and using sulfuric acid slag to grind The equipment is ground to 300μm to obtain the product.
Introduction of sulfuric acid slag utilization grinding equipment: Sulfuric acid slag has great pollution to the environment, but it is a very valuable secondary resource. It has a wide range of applications in building materials, extracting valuable precious metals, and preparing iron-based products. Application prospects: In the past ten years, domestic and foreign researchers have made great progress in the application of pyrite slag in biopharmaceuticals. The use of sulfuric acid slag is inseparable from the assistance of grinding equipment. Sulfuric acid slag is mostly pyrite sintering slag, which is agglomerated dry slag, suitable for dry grinding. The Raymond mill, vertical grinding mill and other equipment produced by Guilin Hongcheng are all dry milling equipment that can help the utilization of sulfuric acid slag. It can process sulfuric acid slag powder with a fineness of 3-380μm. The output and equipment model can be selected according to the needs. If you have related requirements for the use of sulfuric acid slag, please leave us a message for equipment details.