CS276859B6 - A method of producing potassium nitrate - Google Patents

Abstract

The purpose of the solution is to produce potassium nitrate from potassium chloride and calcium nitrate, also using mainly calcium nitrate, which in solid form is difficult to apply in agriculture and other industrial sectors, and at the same time, this undemanding technology will produce an economically advantageous product that is in demand on the market.

Description

Potassium nitrate is the most widely used compound of the potassium salt. It is used in agriculture, in the production of explosives, in the glass industry, but also in food processing, mainly in the meat industry. Its production from raw materials, such as the neutralization of potassium hydroxide or potassium carbonate with nitric acid, is suitable for laboratory use. The conversion of potassium chloride with sodium nitrate is the best known method of producing potassium nitrate. The production of potassium nitrate from potassium chloride and nitric acid has several modifications, mainly to remove the liberated hydrogen chloride which is released during the reaction. The mentioned methods of potassium nitrate production are either economically disadvantageous or the by-products of production have caused difficulties in their use and therefore adversely affect the quality of water or the ecology as such.

The design of the production of potassium nitrate according to the present invention solves economic and ecological aspects and can be feasible even in a common chemical company. Simplified, our invention can be defined as the conversion of potassium chloride and calcium nitrate in an aqueous medium with an excess of potassium chloride, in a neutral or slightly acidic medium. The liquid substrate after the separation of potassium nitrate can be used for the production of chloride or calcium carbonate, which are products or compounds usable in the non-chemical industry. The present invention is not energy intensive, which can be considered a plus.

Example 1

In a beaker of 400 ml was added 150 g 50% solution of Ca / NO _3/2 and at 80 DEG C. 69 g KC1 KC1, if complete dissolution 15 ml H ₂ 0. The clear solution was stirred and cooled to 0 and filtered after washing the filter cake with 10 ml of water 15 ° C warm and after drying 78.2 g of KNOg were obtained.

Example 2

15 g of KCl and 11 g of precipitated CaCO ₃ were mixed in a 250 ml beaker. With stirring, 28.0 g of 50% HNO 3 was added. The solution was cooled to 0 ° C. After washing the filter cake with 5 ml of water, 10.3 g of KNO _{3 were} obtained after drying.

Example 3

30 g of KCl, 26 g of Ca / OH / ₂ and 100 ml of H ₂ O were mixed in a washing flask. Nitrogen gases from the production of HNO ₃ , which contained 2600 mg of NOx villas, were admitted to the resulting suspension. After reaching a pH of 6.3, the nitrous gases were stopped. After cooling the mixture to 0 ° C, the procedure was as in Example 1 to give 20.3 g of KNO ₃ .

Claims (2)

PATENT CLAIMS 1. A process for the production of potassium nitrate from calcium nitrate and potassium chloride, characterized in that 0.95 to 2.5 moles of calcium nitrate are treated on 1.85 to 2.5 moles of calcium nitrate so that 15 to 1.2 moles of calcium nitrate are added per 1 mole of calcium nitrate. 100 moles of water, preferably 18 to 30 moles of water, and the resulting mixture is heated for 10 to 100 minutes, preferably 15 to 80 minutes, to a temperature of 40 to 120 ° C, preferably to 45 to 110 ° C, and then cooled. to a temperature of +20 ° C to -10 ° C and the potassium nitrate crystals resulting from the reaction are separated, preferably by centrifugation, the filter cake is washed in a centrifuge with 1 to 3 moles of water per 1 mole of calcium nitrate and the wash water temperature should be +10 to + 5 ° C, the washing water being used to dissolve the mixture of potassium chloride and calcium nitrate. 2. The process according to item 1, characterized in that the pH of the reaction mixture is maintained in the range of 7.5 to 1.0, preferably 6.5 to 3.5.