Ferrous sulfate used as fertilizer in crop growth and agricultural application

2020/10/27

Synthesis of potassium sulfate from ferrous sulfate

Potassium sulfate is a non-chlorine water-soluble potassium fertilizer, and it is an important way to supplement potassium and sulfur in tobacco, grapes and other economic crops. Preparation of sulfur by reaction of ferrous sulfate and potassium chloride abroad

Synthesis of potassium sulfate from ferrous sulfate

There are more reports on potassium acid, but relatively few domestic studies. Poland, Finland and other countries disclosed in the 1980s that ferrous sulfate and potassium chloride were used as main raw materials to prepare potassium sulfate fertilizers by metathesis or extraction methods. Due to the high cost of synthesis of potassium sulfate by extraction, it has not been put into production yet.

It is proposed to use ferric potassium sulfate conversion method to prepare fertilizer grade potassium sulfate. This method firstly reacts ferrous sulfate with potassium chloride to form potassium iron sulfate double salt (FeSO4·K2SO4·4H2O), and the double salt reacts with remaining potassium chloride in an aqueous solution to form potassium sulfate. Using the by-product ferrous sulfate as the raw material to prepare potassium sulfate is an effective way for the resource utilization of the by-product ferrous sulfate. However, the synthesis process is complex and consumes a lot of energy. Whether the process can be simplified and energy consumption can be reduced is the key to the promotion and use of this process in the future. In addition, the process of preparing potassium sulfate only uses the sulfur resources in the by-product ferrous sulfate of titanium white, and the iron resources are still unused, which is the main defect of the process.

Synthesis of Manganese Sulfate from Ferrous Sulfate

Manganese sulfate is one of the trace elements needed during the growth of crops, which helps to promote the growth of crops and increase yield. Under acidic conditions, the by-product ferrous sulfate is used to reduce pyrolusite to prepare manganese sulfate. The reaction process is as follows:

Synthesis of Manganese Sulfate from Ferrous Sulfate

Using by-product ferrous sulfate as a reducing agent for pyrolusite can effectively reduce the production cost of manganese sulfate, and also relieve the environmental pressure caused by ferrous sulfate. Therefore, the reduction and leaching of pyrolusite with ferrous sulfate has been reported in many literatures. The by-product ferrous sulfate is used to reduce pyrolusite to prepare manganese sulfate, and the synthesis process parameters are optimized to obtain high-purity manganese sulfate. This process takes advantage of the reducibility of ferrous sulfate, and the sulfur in ferrous sulfate has not been effectively utilized. In addition, in the process of reducing pyrolusite with ferrous sulfate, iron generates new waste residue. Therefore, ferrous sulfate is used as a reducing agent to prepare manganese sulfate, which fails to relieve the pressure of environmental pollution.

Synthesis of ammonium sulfate from ferrous sulfate

Ammonium sulfate can be used as base fertilizer, seed fertilizer and top dressing for crops, which can promote the lush foliage of crops, increase the yield of agricultural products, and enhance the ability of crops to resist disasters. Ammonium sulfate has good fertilizer effects on many crops, such as wheat, naked oats, rice and so on. The by-product ferrous sulfate is used as the basic raw material to prepare ammonium sulfate by wet method. First, a certain amount of by-product ferrous sulfate was dissolved in deionized water, and ammonium bicarbonate was added while stirring. After the addition, the temperature of the solution was raised to 60°C for 60 minutes, and then filtered while hot. The filter cake was used to prepare iron red. The filtrate is heated to 80°C, oxidized, and filtered while it is hot. The filtrate is evaporated and concentrated under vacuum and then cooled and crystallized. The product obtained meets the requirements of GB535-1995 "Ammonium Sulfate". The by-product ferrous sulfate is used as the raw material to prepare iron red and ammonium sulfate, which not only achieves good economic benefits, but also reduces the waste of iron sulfide resources, and at the same time reduces the pressure of environmental pollution.