Production method of potassium salt

Abstract

The invention provides a manufacturing method of sylvite, the steps comprise potassium mineral decomposition, froth flotation, dual-level filtration and reusing of waste and brine, wet materials filtration, washing, centrifugation and drying, and then the product is obtained. The invention solves the problems that the existing production technique for sylvite is high in fresh water consumption, high in potassium ion loss, high in froth flotation waste and brine discharge amount and polluted in organic pollution in salt field and the like. The manufacturing method of sylvite is simple in routing, low in fresh water consumption, high in potassium ion recovery rate, low in froth flotation waste and brine discharge amount, high in availability of resources and the like.

Description

Technical field: [0001] The invention relates to potassium chloride, in particular to a production method of potassium salt. Background technique: [0002] my country is a country that consumes a large amount of potassium salt, but it is also a country that is very scarce in potassium resources. my country's potassium salt reserves are mainly concentrated in the Qaidam Basin in Qinghai and the Tarim Basin in Xinjiang, and the potassium salt is mainly potassium chloride. The main production method of salt is the "cold crystallization-flotation" combined process method. This process requires that the potassium-containing minerals be hydrolyzed to obtain potassium chloride crystallization, and then enter the flotation process to select the target product with the help of the flotation agent. The goal of purifying products is achieved by permanent flotation separation. This process has low energy consumption, low construction investment, and simple technical process, but the produ...

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Problems solved by technology

[0002] my country is a country that consumes a large amount of potassium salt, but it is also a country that is very scarce in potassium resources. my country's potassium salt reserves are mainly concentrated in the Qaidam Basin in Qinghai and the Tarim Basin in Xinjiang, and the potassium salt is mainly potassium chloride. The main production method of salt is the "cold crystallization-flotation" combined process method. This process requires that the potassium-containing minerals be hydrolyzed to obtain potassium chloride crystallization, and then enter the flotation process to select the target product with the help of the flotation agent. The goal of purifying products is achieved by permanent flotation separation. This process has low energy consumption, low construction investment, and simple technical process, but the production process consumes a lot of water, which leads to the destruction of the balance of the water-salt system, the decrease in the yield of potassium ions, and the increase in the discharge of waste brine. , a serious waste of resources

According to research and practice, flotation reagents have an inhibitory effect on the decomposition and crystallization of potassium minerals, so the waste brine from flotation has not been directly used. At present, the discarded waste brine has formed a vast lake area, and the waste brine discharged into the lake area, except for a part of precipitation Extracrystalline (MgCl 2 ·6H 2 O), most of which are lost in the storage process, and return to the original brine of the salt lake in the form of leakage, which will inevitably cause the chemical composition of the original brine to be out of balance for a long time, endanger the further development of the salt lake resources, and increase the recovery of potassium Cost and energy consumption, reducing the operating efficiency of equipment and the degradation rate of organic matter

At present, under the concept of protecting the ecological environment, improving resource utilization, and achieving sustainable development, how to improve the status quo of large water consumption, large amount of waste brine, and low product yield is an urgent problem to be solved. question

[0003] The United States, Chile, Israel and other countries are currently the most reasonable and advanced countries in the development and utilization of salt lake brine resources in the world. The development model is the comprehensive utilization of brine resources and the development of series products, so as to minimize production costs and Industrial pollution, but there are also phenomena such as waste of resources in terms of potassium salt yield. For example, after mineral flotation in the Great Salt Lake in Utah, USA, the waste brine from the flotation tank is directly discharged into the salt pan, and a small amount of potassium salt is recovered through evaporation and crystallization

[0004] Domestically, the comprehensive utilization of brine resources has not yet been realized due to technical constraints, and the treatment of flotation waste brine is mainly discharged into the lake area (it is estimated that about 30 tons of waste brine will be discharged for every ton of potassium chloride produced in the Chaerhan area, from Since 2000, the Kunlun Mining Company and Salt Lake Group in the Chaerhan area alone have discharged about 100 million m3 of waste brine 3 / a), the arbitrary discharge of waste halogen not only reduces the grade of minerals in the mining area, but also pollutes resources

There are also many new technologies about the utilization of flotation waste brine at present, such as "a kind of method for making low-sodium carnallite by mixing brine" invented by the Lianyungang Design and Research Institute of the Ministry of Chemical Industry. CN1608995 combines flotation waste brine (F point brine) with Carnallite saturated brine (E point brine) is mixed in a certain proportion in the brine blending device to obtain low-sodium carnallite, but the process of blending brine cannot be accurately grasped, the system recovery rate is low, and the waste of resources is serious; The technology of brine refilling and dissolving potassium is to refill waste brine and fresh water into a certain proportion of solvent to dissolve solid potassium ore in salt lakes. This technology has problems such as organic pollution, complicated process, and difficult operation; Wei Junying in CN1587047 proposed including Pre-drying, tanning, storage, freezing and separation of waste brine, dissolution and crystallization of crude potassium chloride, and a set of methods for refining crystalline potassium chloride on the use of flotation waste brine, but the process is cumbersome, the operation is complicated, and potassium ions Unstable yield

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