CN1175130C - Method for cooling manganese electrolyzing cathode liquid outside tank and recovering magnesium - Google Patents

Abstract

The present invention relates to a method for cooling manganese electrolysis cathode liquid outside a tank and for recovering magnesium, which belongs to the field of metallurgy. An electrolysis method for producing metal manganese is characterized in that a cooling metal pipe for passing water into a manganese electrolysis tank is cancelled; in the state of relatively stable height difference of anolyte liquid levels of a manganese electrolysis catholyte and a membrane, a part of catholyte is led out of an electrolysis tank for cooling down. A technological parameter is strictly controlled, and the recovery of magnesium, manganese and ammonium sulfate is realized. The method for cooling manganese electrolysis cathode liquid outside a tank has the advantages of control of normal operation temperature of the electrolysis tank, high heat exchange effectiveness, good production quality and great reduction of production cost.

Description

The recovery method of outer cooling of a kind of manganese electrolysis cathode liquid bath and magnesium

The invention belongs to field of metallurgy, electrolytic process is produced manganese metal.

Traditional electrolytic process is produced manganese metal and is adopted aqueous solution diaphragm electrolysis sedimentation, and electrolyzer is made negative electrode with stainless steel, and anode is made of lead 2-base alloy, places to contain with a false bottom electrolyzer inner septum bag, and electrolytic solution flows in electrolyzer.Electrolytic solution (catholyte) flows into the anolyte compartment through cathode compartment by barrier film.Electrolytic anode liquid is discharged through the bottom land drainage.

Because Mn in the electrolytic process ²⁺Electrocaloric effect when negative electrode is separated out constantly produces joule heating, adds the anti-molten heat release of the manganese of separating out on top, and the catholyte temperature in the electrolyzer is raise.

In order to get rid of the unnecessary heat in the catholyte, the normal operation temperature of control electrolyzer, countries in the world electrolytic manganese factory all adopts the both sides in electrolyzer to add metallic conduit (lead pipe or aluminium-alloy pipe etc.) in decades, feeds water coolant in pipeline, indirectly the catholyte in the cool electrolysis cells.This method at the electrolyzer internal cooling is because the cooling contact area of cooling duct and catholyte is little, can only make catholyte cooling near cooling tube, the electrolyzer centre of heat production maximum can not get cooling, and whole electrolyzer temperature is inhomogeneous, and heat exchanger effectiveness is low; Catholyte flow rate in electrolyzer is low, makes the more difficult performance cooling effect of the not high cooling tube of original thermal conductivity, MgSO ₄, CaSO ₄With (NH ₄) ₂SO ₄Deng mass crystallization so that the negative electrode working spaces needs frequent cleaning, plant factor is low, labour intensity is big; Simultaneously because the existence of metal cooling-pipe in this electrolyzer, it is big also to make this method have a power consumption, high material consumption, the defective that consumption of cooling-water is big.

The objective of the invention is to improve existing electrolytic process of producing manganese metal, make it not only can control the normal operation temperature of electrolyzer, heat exchanger effectiveness height, and good product quality reduce production costs greatly.

The present invention is for achieving the above object, and the technical scheme of employing is: the cool metal pipe of the feeding water of traditional usefulness in the cancellation manganese electrolytic cell; Under the metastable state of the anolyte liquid level discrepancy in elevation in keeping manganese electrolysis cathode liquid and barrier film, the part catholyte is drawn outside the electrolyzer,,, cool off by air blast or natural wind by efficient anti-crystallization nozzle; Along with the cooling of catholyte, the Mg in the solvent ²⁺, Ca ²⁺Solubleness descend MgSO ₄, CaSO ₄With (NH ₄) ₂SO ₄Reduce in the sedimentation of cathode compartment intercrystalline.Excessive calcium magnesium is separated out in crystallization in chute or collecting tank, regularly goes out crystallisate clearly, thereby removes part MgSO in the solution ₄, CaSO ₄Deng impurity, and efficient recovery magnesium, manganese and ammonium sulfate; Turn back to the cathode compartment of electrolyzer through the gravity flow of the cooling catholyte of collecting tank or with pump, be controlled at and carry out electrolysis under the normal operation temperature continuously; The processing parameter of control is:

34 ℃～36 ℃ of the temperature of catholyte adding electrolyzer go out 40 ℃～43 ℃ of electrolyzer temperatures, 40 ℃～43 ℃ of cooling infrastructure feed liquor temperature, 34 ℃～36 ℃ of cooling back solution temperatures;

When advancing electrolyzer, catholyte contains Mn ²⁺20～22g/L goes out electrolyzer Mn ²⁺Be 14～18g/L, pH is 7～7.5;

Cathode area (wide * height) 400mm～660mm * 500～1000mm, negative electrode immerses the height 480～980mm in the catholyte, homopolarity width between centers 70～86mm.Cathode current density 350～420A/m ², anodic current density 480～572A/m ²

The present invention's remarkable advantage and positively effect compared with the prior art is:

1. catholyte is guided to outside the electrolyzer in electrolyzer and cooled off, realized the amount of flow and the temperature controlling of anticathode liquid.Suitably strengthen amount of flow, electrolyzer inner cathode chamber flow of solution speed improves, and makes negative electrode room temp and Mn ²⁺Concentration distribution is even, and heat exchange effect is good; Significantly reduced MgSO ₄, CaSO ₄In cathode compartment intercrystalline sedimentation phenomenon, promptly reduced the cleaning of anticathode chamber, improved plant factor, reduced labour intensity, improved production environment.

2. catholyte is guided to outside the electrolyzer in electrolyzer and cooled off, also realized recovery magnesium manganese and ammonium sulfate.

3. remove water-cooled tube in electrolyzer, make the effective rate of utilization of electrolyzer improve 12%, throughput can improve 10%～12%.

4. enforcement of the present invention not only can be controlled the normal operation temperature of electrolyzer, and heat exchanger effectiveness height, and good product quality reduce production costs greatly.The 36h that works continuously, cathode compartment do not have any crystallisate sedimentation and produce cathode compartment Mn ²⁺The full groove of concentration is even, is no more than the scope of 14～18g/L; Each measurement of bearing pH of the full groove of cathode compartment is 7～7.5; Behind the electrolysis 36h, negative electrode Mn sampling analysis contains Mn99.80%, and quality meets GB-418-82 first grade standard;

Be further described below in conjunction with accompanying drawing:

Accompanying drawing 1: be process flow diagram of the present invention.

Accompanying drawing 1 has been described the removal process of outer cooling of manganese electrolysis cathode liquid bath of the present invention and magnesium:

1. electrolyzer is made negative electrode with stainless steel, makes anode with lead 2-base alloy, places to contain with a false bottom electrolyzer inner septum bag, and electrolytic solution (catholyte) flows in electrolyzer.Electrolytic solution flows into the anolyte compartment through cathode compartment by barrier film.Electrolytic anode liquid is discharged through the bottom land drainage.The cool metal pipe of the feeding water of traditional usefulness in the cancellation manganese electrolytic cell.

2. under the metastable state of the anolyte liquid level discrepancy in elevation in keeping manganese electrolysis cathode liquid and barrier film, the part catholyte is drawn outside the electrolyzer, by efficient anti-crystallization nozzle, air blast or by natural wind is cooled off; The amount of flow and the temperature controlling of anticathode liquid have been realized.Suitably strengthen amount of flow, electrolyzer inner cathode chamber flow of solution speed improves, and makes negative electrode room temp and Mn ²⁺Concentration distribution is even, and heat exchange effect is good.

3. along with the cooling of catholyte, the Mg in the solvent ²⁺, Ca ²⁺Solubleness descend MgSO ₄, CaSO ₄With (NH ₄) ₂SO ₄Reduce in the sedimentation of cathode compartment intercrystalline, excessive calcium magnesium is separated out in crystallization in chute or collecting tank, regularly goes out crystallisate clearly, thereby removes part MgSO in the solution ₄, CaSO ₄Deng impurity, and efficient recovery magnesium, manganese and ammonium sulfate; The part catholyte guided to outside the electrolyzer in electrolyzer cool off, realized recovery magnesium manganese and ammonium sulfate.

Through the cooling of collecting tank, catholyte gravity flow or turn back to the cathode compartment of electrolyzer with pump is controlled at and carries out electrolysis under the normal operation temperature continuously.The processing parameter of control is:

34 ℃～36 ℃ of the temperature of catholyte adding electrolyzer go out 40 ℃～43 ℃ of electrolyzer temperatures, 40 ℃～43 ℃ of cooling infrastructure feed liquor temperature, 34 ℃～36 ℃ of cooling back solution temperatures.Temperature is uniform and stable in the groove, and the cooling width of cloth difference of cooling infrastructure is wide.

When advancing electrolyzer, catholyte contains Mn ²⁺18～22g/L goes out electrolyzer Mn ²⁺Be 14～18g/L, pH is 7～7.5.

Cathode area (wide * height) 400～660mm * 500～1000mm, negative electrode immerses the height 480～980mm in the catholyte, homopolarity width between centers 70～86mm.Cathode current density 350～420A/m ², anodic current density 480～572A/m ²

The 36h that works continuously, cathode compartment do not have any crystallisate sedimentation and produce cathode compartment Mn ²⁺The full groove of concentration is even, is no more than the scope of 14～18g/L; Each measurement of bearing pH value of the full groove of cathode compartment is 7～7.5.

Behind the electrolysis 36h, negative electrode Mn sampling analysis contains Mn99.80%, and quality meets the GB-418-82 first grade.

Claims (1)

1. the recovery method of outer cooling of a manganese electrolysis cathode liquid bath and magnesium is characterized in that: the cool metal pipe of the feeding water of traditional usefulness in the cancellation manganese electrolytic cell; Under the metastable state of the anolyte liquid level discrepancy in elevation in keeping manganese electrolysis cathode liquid and barrier film, the part catholyte is drawn outside the electrolyzer,,, cool off by air blast or natural wind by efficient anti-crystallization nozzle; Along with the cooling of catholyte, the Mg in the solvent ²⁺, Ca ²⁺Solubleness descend MgSO ₄, CaSO ₄With (NH ₄) ₂SO ₄Reduce in the sedimentation of cathode compartment intercrystalline, excessive calcium magnesium is separated out in crystallization in chute or collecting tank, regularly goes out crystallisate clearly, thereby removes part MgSO in the solution ₄, CaSO ₄Impurity, and efficient recovery magnesium, manganese and ammonium sulfate; Turn back to the cathode compartment of electrolyzer through the gravity flow of the cooling catholyte of collecting tank or with pump, be controlled at and carry out electrolysis under the normal operation temperature continuously; The processing parameter of control is:

34 ℃～36 ℃ of the temperature of catholyte adding electrolyzer go out 40 ℃～43 ℃ of electrolyzer temperatures, 40 ℃～43 ℃ of cooling infrastructure feed liquor temperature, 34 ℃～36 ℃ of cooling back solution temperatures;

When advancing electrolyzer, catholyte contains Mn ²⁺20～22g/L goes out electrolyzer Mn ²⁺Be 14～18g/L, pH is 7～7.5;

Cathode area is wide * high 400～660mm * 500～1000mm, and negative electrode immerses the height 480～980mm in the catholyte, homopolarity width between centers 70～86mm; Cathode current density 350～420A/m ², anodic current density 480～572A/m ²

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