SU1225878A1 - Method of producing basic nickel carbonate - Google Patents

Description

The invention relates to electrochemical production, in particular, to a method for producing nickel carbonate, which is a raw material for producing nickel (II) oxide.

The purpose of the invention is to reduce the consumption of reagents while maintaining a high current efficiency.

The process technology is as follows.

Metallic nickel is subjected to anodic dissolution in the electrolyte, which is an aqueous solution of ammonium bicarbonate with a concentration of 8–15 g / l, and ammonium carbonate with a concentration of 0.5–1.0 g / l. At the same time, uninterrupted bubbling of the flue gases of the boiler production through the electrolyte is carried out. Electrolyte can be used repeatedly after adjusting it for missing components. The washings formed after the washing of the nickel salts are recycled to the electrolyte preparation process. Thus, the process is waste-free production.

To dissolve metallic nickel, it is possible to use electrolyzers with a bipolar arrangement of electrodes, which allows an increase in the productivity of the process.

When the concentration of ammonium bicarbonate is below 8 g / l, ammonium carbonate is below 0.5 g / l, ammonium chloride is below 0.5 g / l, the nickel electrode is passivated, which leads to a decrease in metal dissolution rate and, of course, current efficiency.

Use electrolyte with. ammonium bicarbonate concentration above 15 g / l, ammonium carbonate above 1 g / l ammonium chloride above 1.5 g / l is impractical because of the salt passivation of nickel electrodes arising under these conditions. This impedes the transition of nickel ions into solution, the dissolution rate decreases, and the current efficiency drops.

Example 1. In a cell with two leading nickel electrodes serving as the anode and cathode, and between them nine bipolar nickel electrodes located between them, dissolves metallic nickel under the action of direct current in the electrolyte.

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ammonium bicarbonate aqueous solution with a concentration of 8 g / l, ammonium carbonate with a concentration of 0.5 g / l and ammonium chloride with a concentration of 0.5 g / l with continuous bubbling through the electrolyte of a boiler plant of the following composition, %: CO 7.5; 7.9; Nj - 84.6.

Process parameters: flue gas feed rate of 18 l / min, cathode current density of 7 A / dm, anode current density of 0.8 A / dm, nickel dissolution rate (ten bipolar electrodes). 8.76 g / h-dm, current output 100%, substance yield 100%.

Example 2. The electrolysis process is carried out in the same cell as in example 1.

Process parameters: electrolyte - ammonium bicarbonate aqueous solution with a concentration of 10 g / l, ammonium carbonate with a concentration of 0.75 g / l, ammonium chloride with a concentration of 1 g / l, flue gas feed rate of 18 l / min, a cathode current density of 8 A / dm, anode current density 1 A / dm, nickel dissolution rate 10.95 g / dm-h, current output 100%, substance yield 100%.

Example 3. The electrolysis process is carried out in the same cell as in example 1.

Process parameters: electrolyte - ammonium bicarbonate aqueous solution with a concentration of 15 g / l, ammonium carbonate with a concentration of 1 g / l, ammonium chloride with a concentration of 1.5 g / l, flue gas feed rate of 27 l / min, anode current density 1.5 A / dm, cathode current density. 12 A / dm, the rate of dissolution of nnke-g l 16.43 g / h dm, current yield 100%, substance yield 100%.

Example 4. The electrolysis process is carried out in the same cell as in example 1.

Process parameters: electrolyte - ammonium bicarbonate aqueous solution with a concentration of 6 g / l, ammonium carbonate with a concentration of 0.4 g / l, ammonium chloride with a concentration of 0.3 g / l, flue gas flow rate of 18 l / l, cathode density current 6 A / dm, anode current density of 0.6 A / dm, the rate of dissolution ni.

kel 6 g / h-dm, current output 90%, substance yield 100%.

Example 5. The electrolysis process is carried out in the same cell as in example 1.

Process parameters: electrolyte - ammonium bicarbonate aqueous solution with a concentration of 18 g / l, ammonium carbonate with a concentration of 1.3 g / l, ammonium chloride with a concentration of 2 g / l, dm gas feed rate 32 l / h, cathodic current density 14 A / dm, anode current density 1.8 A / dm, nickel dissolution rate 17.74 g / h dm, current output 90%, substance yield 100%.

Example 6. The electrolysis process is carried out in the same cell as in example 1,

Process parameters: electrolyte - aqueous solution of ammonium carbonate with a concentration of 10 g / l, ammonium chloride with a concentration of I g / l, flue gas feed rate of 18 l / min, cathode current density 8 A / dm, anode current density 1 A / dm, nickel dissolution rate of 10.95 g / h l dm, current output 100%, substance yield 100%.

The proposed method allows to obtain the basic nickel carbonate of nickel of composition 5NiCO, (2-3.) Ni (ON2) 48-10.,

The compound has more NiCO molecules in its structure. The precipitate is quickly filtered (the duration of the stage is 6 hours), it is easily removed from the impurity ions, which reduces the duration of these operations and co-editor A. Kozoriz

Compiled by O. Zobnin

Tehred I.Popovich Proofreader M. Pojo

Order 2106/20 Circulation 615 Subscription Win-Win State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab., 4/5

. Production and printing company, Uzhgorod, Projecto st., 4

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The amount of wastewater is approximately 3 times.

In addition, the temperature of calcination decreases (from 800 to) and the time of calcination (from 15 hours to 6 hours) when using basic nickel carbonate of composition 5Н1СО - (2-3) Ni (OH) "(8-10) HjO as the starting , a product for producing nickel (II) oxide used in electronic industry; instead of carbon dioxide gas, flue gas from boiler house of the following composition is used,%: COj 6-7.5; 0 7-8; N, j 84-: 85, which contributes to the disposal of waste from boiler production and leads to the protection of the environment from harmful emissions;

the consumption of reagents per 1 kg of the finished product is reduced due to the use of an electrolyte with a low concentration of components (8-15 g / l. of ammonium bicarbonate, 0.5-1.0 g / l of ammonium carbonate, 0.5-1.5 g / l ammonium chloride versus 20-30 g / l ammonium carbonate and g / l ammonium chloride (known); instead of food ammonium bicarbonate, ammonium ammonium salt is used, which is a mixture of various carbonates, mainly ammonium bicarbonate (75-88%) and ammonium carbonate (6-12%), which is a large-tonnage product. The cost of ammonium carbon layers below the cost of ammonium bicarbonate and ammonium carbonate is five times; Scarlet ammonium carbonate and carbon dioxide are required for the food industry.

Claims (2)

1. METHOD FOR PRODUCING BASIC CARBON DIOXIDE NICKEL SALT by • anodic dissolution of metallic nickel in an aqueous electrolyte containing ammonium carbonate and chloride, while bubbling carbon dioxide, characterized in that, in order to reduce the consumption of reagents while maintaining a high current efficiency, dissolution is carried out in an electrolyte additionally containing ammonium bicarbonate 0.5-1.5 g / l. 2. The method of pop. 1, characterized in that as the carbon dioxide use flue gases of a boiler production.