Background and overview[1]
Tripotassium phosphate, also known as potassium phosphate, is a white granular powder, easily hygroscopic, with a relative density of 2.564 (17°C) and a melting point of 1340°C. Soluble in water, showing alkaline reaction. Insoluble in ethanol. Used as water softener, fertilizer, liquid soap, food additive, etc. It can be prepared by adding potassium hydroxide to dipotassium hydrogen phosphate solution.
Preparation[2]
The current production method is mainly the neutralization method, that is, after reacting phosphoric acid with potassium hydroxide or potassium bicarbonate or potassium carbonate, through the control of the reaction end point, the neutralized liquid is concentrated and the insoluble liquid is removed. The product is then cooled and crystallized, centrifuged and dried to obtain the product. However, since phosphoric acid is divided into thermal phosphoric acid and wet phosphoric acid, wet phosphoric acid mainly uses phosphate rock and inorganic acid to produce weak acid according to the principle of strong acid. Even if inorganic acid, such as sulfuric acid, is used to leach the phosphorus element, the sulfuric acid It is obtained by filtration after the roots and other elements, such as calcium, form calcium sulfate insoluble matter.
However, because the quality of phosphate rock will affect the quality of wet phosphoric acid, the quality of phosphoric acid products prepared by wet phosphoric acid is unstable. At the same time, the impurity content in the obtained phosphoric acid is higher and the purity is lower. Low, so when using phosphoric acid prepared by wet phosphoric acid to produce potassium phosphate products, it will not only make the purity of potassium phosphate lower and the quality unstable, but also cause the addition of potassium hydroxide or potassium phosphate during the preparation process. The potassium ions in potassium carbonate and potassium bicarbonate interact with other impurity elements to form insoluble matter, which in turn causes a waste of potassium ions and increases the amount of potassium hydroxide, potassium carbonate or potassium bicarbonate added, resulting in higher preparation costs and resource loss. Consumption is large.
On the basis of the existing preparation process of tripotassium phosphate, research is conducted to provide a method for preparing tripotassium phosphate from wet phosphoric acid, which includes the following steps:
(1) Take wet phosphoric acid with a phosphorus pentoxide concentration of 15%, analyze the sulfate content in it, and add phosphate rock powder to it. The amount of phosphate rock powder added is equal to the sulfate content. The mass ratio is 1:1. After the reaction for 30 minutes, add ammonia water or pass ammonia gas into it, adjust the pH value to 3, and filter to obtain slurry and filter residue;
(2) Take potassium hydroxide, add potassium hydroxide to the slurry, control the molar ratio of the amount of potassium hydroxide to the amount of phosphorus pentoxide in the wet phosphoric acid to 6:1, wait until it is fed After completion, control the negative pressure to 0MPa and evaporate and crystallize at a temperature of 85°C. When a large number of crystals appear in the solution, stop evaporation, cool to room temperature, and filter to obtain the mother liquor and preliminary finished product. The preliminary finished product is washed to obtain tripotassium phosphate.
The purity of tripotassium phosphate is 98.1%. In the described washing, the washing liquid produced by the washing is returned to step 1 and mixed with wet phosphoric acid. In the described evaporation crystallization, the gas generated during the crystallization process is absorbed by dilute phosphoric acid, and then returned to be mixed with the wet phosphoric acid in step 1. The concentration of dilute phosphoric acid is 15%. The mother liquor is sent to the compound fertilizer production line; the filter residue is sent to the compound fertilizer production line. The potassium hydroxide is added to the slurry as a solid. The content of phosphorus pentoxide in the phosphate rock powder is not less than 7%. The particle size of the phosphate rock powder is 40 mesh.
Application [3-4]Emulsifying Thickener
With the continuous advancement of science, alloys are used more and more widely, whether in transportation, daily necessities, household items, etc., such as: automobile industry, building materials industry, kitchen supplies, alloy supplies are used in daily life It has played a considerable role, but many alloy materials on the market now have poor oxidation resistance and high cost, especially in the field of various vehicle engines that are prone to wear. The main technical problem to be solved is to provide a high-temperature oxidation-resistant metal product with good oxidation resistance.
In order to solve the above technical problems, one technical solution adopted is to provide a high-temperature oxidation-resistant metal product, including: a first layer of material and a second layer of material. The first layer of material is made of iron, titanium, and scandium. and manganese. The second layer material is composed of tripotassium phosphate, silicon nitride, graphene, cerium and aluminum. The weight parts of each component in the first layer material are: 50-60 parts of iron and 10 parts of titanium. -22 parts, scandium 1-8 parts and manganese 2-10 parts. The weight parts of each component in the second layer material: tripotassium phosphate 10-18 parts, silicon nitride 20-30 parts, graphene 11 -19 parts, 1.5-2.4 parts of cerium and 40-50 parts of aluminum. In the high-temperature oxidation-resistant metal product, the first layer of material is above the second layer of material and is connected by seamless welding.
Tripotassium phosphate can also be used to prepare a plant growth regulating composition containing 6-benzylaminopurine. The plant growth regulating composition includes the following components, each component is by weight: A, 0.05- 5 parts of 6-benzylaminopurine; B. 10-30 parts of at least one selected from tripotassium phosphate, trisodium phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, potassium tripolyphosphate, sodium tripolyphosphate, tetrahydrofuran Alkaline components of sodium octaborate, potassium tetraborate, borax, triethanolamine, and ethanolamine; and C, 5-30 parts of at least one selected from the group consisting of disodium EDTA, calcium EDTA, magnesium EDTA, calcium disodium EDTA, and disodium EDTA Magnesium, Sodium Citrate and Potassium Citrate.
Main reference materials
[1] Concise Dictionary of Fine Chemicals
[2] CN201510606956.0
[3] CN201810424536.4
[4]CN201210429734.2
