How to Operate Normal Temperature&Pressure Gold Desorption Electrolysis System
This equipment is specially designed for small-scale gold mine carbon slurry plants and heap leaching-carbon adsorption process gold-loaded carbon desorption electrolysis, direct production of composite gold design. It has the characteristics of compact structure, movable, complete functions, complete supporting facilities, simple operation, and high efficiency.
Gold desorption electrolysis system Equipment composition
1. Desorption column 2. Electric heater 3. Heat exchanger 4. Electrolysis cell 5. Desorption electrolysis electric control cabinet 6. 32CQ-25 magnetic circulation pump
Desorption Electrolysis System Equipment performance
Desorption Electrolysis System Equipment List
1. Production capacity: 300 kg dry carbon per batch
2. Equipment weight: 3000 kg
3. Occupied space: length × width × height = 4 × 2 × 3.6 meters
4. Desorption rate: ﹥96%
5. Electrolysis rate: ﹥99%
6. Installed capacity: 30KW
Desorption electrolysis system equipment installation instructions
1. Desorption column:
The desorption column is made of steel welded joints, with a 20 mesh stainless steel screen at the bottom and a filter cartridge made of 20 mesh stainless steel mesh at the top. It can hold 300 kg of activated carbon, and the desorption temperature is 95 ℃, which is not allowed use over temperature.
2. Electric heater
The electric heating tube is made of stainless steel. There are 6 electric heating tubes with 220V(standard, can be customized) and 4KW resistance wires, which are installed in a steel plate welded cylinder to form an electric heater with a total power of 24KW. There is one AH28-6 full-open spring safety valve on the top of the electric heater, and one safety valve is sealed with a 4 mm thick rubber sheet. When the temperature rise in the electric heater is too high, once
the safety valve is activated, the liquid will be desorbed. Flow back to the sump. This process prevents the high-temperature desorption liquid from spraying and scalding people and causing the loss of precious liquid. When this accident occurs, stop immediately, find out the cause, and deal with it.
3. Heat exchanger
There are 109 seamless steel pipes in the cylindrical steel plate, with a total heat exchange area of 15 square meters. The high-temperature precious liquid from the desorption column flows in the steel pipe. After being cooled by the lean liquid outside the steel pipe, it enters the electrolytic cell. At the place where the precious liquid enters, a 20-mesh stainless steel mesh is installed to filter the precious liquid entering the electrolytic cell. This equipment has a filter cartridge at the outlet of the expensive liquid of the desorption column and a filter screen in the heat exchanger, so no additional filter is required.
4. Electrolysis cell
The electrolytic cell is made of polypropylene plate, which can withstand the temperature of 80℃, the anode is made of stainless steel plate, the specification is 400× 500 mm, 11 anode plates, 10 cathode plates (using φ0.13 stainless steel microwire or carbon fiber).
5. Desorption electrolysis electric control cabinet
The desorption electrolysis electric control cabinet is a kind of electric control equipment specially developed by our company for desorption electrolysis. It supplies DC power to the electrolysis cell, controls the magnetic pump and heater, and automatically controls the heating of the desorption solution.
Normal Temperature&Pressure Gold Desorption Electrolysis System Precautions for use:
1. The ambient temperature does not exceed +40℃ and is not lower than -10℃.
2. The relative humidity of the surrounding environment does not exceed 85% at 20°C and does not exceed 50% at 40°C.
3. There is no conductive and explosive dust around, no gas or steam that corrodes metal, and damages insulation.
4. Install in a place with good ventilation, no severe vibration and impact, and a vertical tilt not exceeding 5°
Technical data
1. Rated input voltage: three-phase four-wire 380V50HZ (can customize voltage). It is recommended to use 3*25+1 for the incoming copper core cable, the live wire is connected to the upper end of the NM1-250 circuit breaker, and the neutral wire is connected to the insulator.
2. DC output voltage: 0-3V.
3. DC output current: 0-200A
Protection System
This equipment adopts two methods of resistance-capacitance protection and varistor. The control circuit has an overcurrent protection link and a module overheat protection link to ensure the safe and reliable operation of the equipment.
Installation and maintenance
Installation requirements
(1) Meet the above conditions of use.
(2) Before the equipment is installed and debugged, check whether the accessories are damaged or dropped off by the impact of vibration during transportation.
(3) The equipment should be installed in a well-ventilated place, free from rainwater immersion and with no corrosive gas and dust.
(4) The equipment shell should be reliably grounded.
Parameters and principles
In order to enable users to master the desorption electrolysis process, some experience of our factory is introduced as follows, for reference only (300Kg):
Desorption time: 44 hours (counted from reaching 95 ℃, adjusted according to poor carbon)
1. Concentration of desorption solution: NaCN≮2% NaOH≮1%
2. Desorption temperature: 95 ℃ (subject to the outlet of the desorption column)
3. Desorption voltage: 3V (DC)
4. Electrolysis current: 200A
5. Electrolyte flow rate: 1.5t/h
6. The initial dosage of medicament: NaCN 40kg, NaOH 20kg. In the future, the content of the drug should be checked regularly before desorption, and the drug should be added when the content is too low.
Process principle:
The gold-loaded activated carbon is configured by sodium cyanide and sodium hydroxide in the desorption column. After the analytical solution is heated, the gold and silver of the gold-loaded activated carbon are precipitated from the carbon to become the precious liquid, and the precious liquid passes through the direct current in the electrolytic cell. Function, gold is deposited on the cathode as gold powder
Equipment function:
The supporting equipment of this device includes
desorption column, electric heater, heat exchanger, Electrolysis cell, desorption liquid storage tank, circulating pump, rectification control cabinet, etc. Among them, the rectifier control cabinet can be used for DC output, electric heating thermostat control, and circulating pump control. When the safety valve is over-pressured, it can act and return to the desorption tank. The desorption liquid circulating pump has multiple functions such as desorption liquid configuration, desorption liquid returning to the electrolytic cell for cleaning, and so on.
Installation:
This equipment does not require an equipment foundation. Before leaving the factory, the pipeline valves, flanges, electrical circuits, etc. have been assembled and tested by trial operation.
1. Elevated plan: If the height of the factory building allows and the
carbon funnel is at a reasonable elevation, the equipment can be raised by 60-70 cm with the support bracket, and the equipment can be leveled.
2. Flat frame plan: If the height of the plant is not allowed, the equipment can be placed on the ground, and a 1.8m square, 60-70 cm deep pit is built under the ground of the desorption column to recover the desorbed carbon and Groundwater.
3. The ground of this equipment should be treated with anti-seepage and leakage prevention, and the ground with conditions can be treated with anti-corrosion.
4. After the power is turned on, the forward and reverse of the magnetic pump must be adjusted. 5. Connect the disassembled desorption column at the flange, and the fastening screws should be symmetrical.
Operating procedures
1. Carbon loading: The gold-loaded carbon added to the desorption column must be cleaned with water. The carbon must not contain debris such as mud and wood chips. After loading the carbon, fasten the top carbon inlet with a blind plate, and check the discharge valve of the desorption column. No ore mud or carbon particles shall be discharged as
the carbon filling is completed.
2. Inspection: After the desorption, the liquid storage tank is filled with clean water, open the pipeline valve to start the circulating pump, check whether the elbows, flanges, valves and other joints are leaking, and check whether the circulating pump is rotating. Note: Only after the liquid storage tank returns. Turn on the heater and observe the liquid level in the liquid storage tank during the first cycle. If the liquid level reaches the inlet of the circulating pump, immediately add clean water to the liquid storage tank to avoid burning the circulating pump due to emptying. At the same time, observe whether the electric heating and electric control are sensitive and normal.
3. Dispensing: Weigh 40kg of sodium cyanide and 20kg of sodium hydroxide. Put it into the desorption liquid storage tank and rinse the medicine with clean water. If the reagent has not been completely dissolved after the storage tank is filled with water, you can turn on the circulation pump to dissolve it with bypass water. After the reagent is completely dissolved, open the straight-through valve.
4. Desorption: Turn on the desorption liquid circulation pump after opening the relevant valve. When the desorption liquid is returned to the liquid return pipe of the electrolytic cell, the electric heater is sent and heated. When the desorption temperature reaches 95 ℃ (observe the temperature controller), turn the electrolytic cell Send in DC and adjust the current to 200A. The desorption electrolysis is continued for at least 44 hours and the desorption electrolysis is over.
5. Stop sequence: stop the electric heater first, then stop the circulation pump, and then shut down the electrolysis power supply. Close the valve of the inlet pipe at the front of the electrolytic cell and slightly open the drain valve of the electrolytic cell to make the lean liquid in the electrolytic cell slowly flow back to the storage tank. The electrolyte in the storage tank must be added according to the concentration after 1-2 times of use.
It is recommended that the lean liquid and cooling flushing water in the desorption column should also be returned to the process. The lean carbon after cooling in the desorption column is discharged from the carbon discharge port. The lean carbon is washed with water, pickled (5% HC1), and then washed with water. Can return to the adsorption section.
6. Gold mud treatment: After the desorption electrolysis is completed, open the electrolytic cell and take out the cathode plate (the electrode plate can also be taken out once after multiple desorption and electrolysis). The gold-loaded steel wool is rinsed in clean water, and the steel wool after elution of the gold mud is re-inserted into the cathode
plate and put into the electrolytic cell for next use. If the electrolytic cell is not used for a long time, it should be filled with water to prevent cracking (please prevent freezing in severe cold areas).
The gold mud is sieved to remove impurities, dried, and smelted to obtain finished gold ingots. In order to improve the fineness of gold, the gold mud can be added with acid, divided into silver, washed, dried, and smelted to obtain gold ingots with higher fineness.
Precautions
1. The desorption temperature of this equipment is rated at 95°C, and the temperature is stabilized during operation, and over-temperature and high-pressure operation is strictly prohibited.
2. If there is a sudden power outage for a long time during operation, the desorption time should be recalculated and should not be accumulated.
3. Pay attention to the adjustment of the inlet valve of the circulating pump during the operation of the equipment. Generally, the excessive temperature difference between the upper and lower sides of the desorption column (>15°C) is caused by the too-small flow rate of the valve. If the temperature difference between the top and bottom of the desorption column is too small (<10°C), it is because the valve is opened and the flow is too large.
4. Sometimes the upper part of the desorption column is blocked by the charcoal screen or too much mud in the charcoal can also cause the temperature difference between the upper and lower sides of the desorption
5. If coarse carbon particles are found at the discharge port of the desorption column, it is caused by the damage of the carbon isolation screen and should be replaced in time. If mud and sand are found in the discharge port, it is caused by the unwashed charcoal
6. If there is any leakage in the pipeline, it should be repaired or recycled in time to avoid the loss of precious liquid.
7. If it is found that the electrolysis current has dropped significantly, most of it is caused by poor contact with the electrode plate, corrosion of the electrode plate, or an open circuit of the power supply. The copper bar of the electrolytic cell should be polished with sandpaper before installing the electrode plate. The electrode plate should be pressed firmly. If the corrosion is serious, the electrode plate should be replaced.
8. During the desorption electrolysis operation, sometimes a large number of bubbles gush out in the electrolytic cell to cause the desorption liquid to overflow. At this time, the lower electrolytic cell drain valve should be opened immediately, and the secondary valve should be closed after the “bubbles” disappear.
9. If it is necessary to stop the pump for maintenance during operation, stop the electric heater first, and then stop the pump to prevent the electric heater from burning due to lack of water
10. Before carbon loading and after electrolysis, samples should be taken separately, gold-loaded carbon, lean carbon, and lean liquid, and the desorption rate and electrolysis rate of the batch should be calculated.
11. Sometimes the desorption temperature cannot be reached for a long time due to the following reasons:
A. Excessive flow of desorption liquid;
B. The outside temperature is too low;
C. Damage effect of insulation layer;
D. One or several groups of electric heating tubes are not working (or burned out);
E. One phase of the power supply is missing;
12. Strengthening equipment insulation and environmental insulation can reduce heating time and avoid wasting energy
