Operating process specification for platinum refining and purification system. 1, platinum refining purification system operation preparation work, open the power-on switch, before the power-on switch, to confirm that all the start switches are in the off state, after the open. In principle, the sequence is that all valve positions and controls are zeroed.
2. Operation of platinum refining and purification system Compressed air pressure test
Pressure test the reactor with compressed air to ensure that there is no chlorine leakage during production,click the pressure test button above PLC. PLC will automatically open compressed air valve F2 open, pressurized to 1 bar after the valve automatically closed, pressure test lasts for 20 minutes, after 10 minutes if the pressure drop is less than 0.015 bar, the screen shows that the pressure test passed, please continue to execute the next step. If the pressure drop exceeds 0.015 bar, indicating a failure of the pressure test, check to ensure that all valves are closed and the nuts are tightened, and then repeat the pressure test. If the stress test fails a second time, notify the supervisor and suspend any production processes until the problem is resolved.
Compressed air is through the inlet pressure regulator pressure and pressure, according to the process requirements of the pressure, adjust the intake pressure value to a stable value can be, open the air inlet switch, you can feed air, because the air pressure has been adjusted, delay for a period of time, you can close the air switch.
3. Operation of platinum refining and purification system Chlorine replacement
Dissolution kettle depressurized. PLC operation: click the pressure relief start button, PLC automatically opens exhaust valve F102, when the pressure is completely relieved, the valve will automatically close.
Chlorine replacement dissolver to remove air. PLC operation: click the Start Dissolution button, chlorine gas inlet valve FV101 and flow meter will be opened, when the pressure in the kettle increases to 1 bar, chlorine valve and flow meter will be closed, automatic exhaust valve F102 will be opened to release pressure, and the gas in the kettle will be directly discharged into the tail gas to the scrubber. Five cycles of chlorine replacement. During the replacement process, ammonia reagent in the spray pot is used to manually test whether chlorine gas leaks, mainly whether the reaction kettle manhole and feeding hole are tight.
After chlorine replacement is completed,input the total chlorine consumption limit (kg)(CL2:pt=1:1) into PLC operation and input the total chlorine demand.
4. Operation of platinum refining and purification system Metal dissolution
Stirring paddle speed is 100%, confirm cooling water automatic mode, start to introduce chlorine into the reactor. PLC operation: Click the chlorine button. Chlorine switch valve FV101 and chlorine flow meter will open to reach and maintain 1 bar. After dissolution begins, the cooling water is automatically turned on, and after reaching the set time, it is automatically adjusted according to the temperature, which does not exceed 50℃. Note: This reaction is exothermic reaction, should observe the cooling water flow and temperature changes in the kettle.
Continue to dissolve. Sponge platinum and atomized platinum reaction rate is different, 100kg sponge platinum dissolution takes 6-8 hours to complete, consumption of about 80kg exothermic chlorine, atomized platinum powder takes longer time. Record the time, chlorine pressure, chlorine flow rate, temperature in the reactor and total chlorine addition every hour. Over time, chlorine flow will gradually decrease, and when dissolution is nearly complete, chlorine flow will decrease significantly.
Dissolve the metal and stop chlorine. When the PLC shows chlorine drops to 0, chlorine valve opening drops to 8% or less and stops. It indicates that CPA dissolution is complete and chlorine gas flow should be stopped. PLC operation: click the stop chlorine button, PLC will close the chlorine switch valve FV101 and chlorine flow meter.
5. Operation of platinum refining and purification system Compressed air replacement
Dissolution complete. PLCoperation: click on the dissolution complete button, the program will cut off chlorine, and launch cooling water automatic control mode. In the reactor command window, click the Start button.
Compressed air replacement, compressed chlorine gas replacement kettle out. PLCoperation: click the compressed air purge button,PLCwill automatically relieve pressure for3times, after the pressure relief is completed, the compressed air valveF2will be opened until the pressure in the reactor reaches0.7 bar, then close the air supply valve, and openF102to release pressure automatically. Until a total of5cycles are completed.
Ventilation inside the kettle. Openair intake valve F2 on PLC,manually open air intake valve, keep ventilation formore than 10 minutes.
6. Operation of platinum refining and purification system Evaporation concentration
When all metals are dissolved and there is no sponge platinum in the reactor, turn off the circulating water in the system, adjust the agitator speed to 50%, and manually open the chilled water inlet on the refrigerator to start concentration. The system automatically opens steam regulating valve F3 110 and condensate drain valve, automatically sets to 105℃, and automatically adjusts steam addition. Unless otherwise specified, manual sampling is sent to QC for analysis and concentrated to a specific gravity higher than (1.90 0.05) to ensure that the CL/pt ratio is 6/1. Record the time, temperature, liquid level and acidity of chilled water condensate every hour during concentration. Generally, concentration is basically completed when the acidity drops below 9%.
Note: At the beginning of concentration, if the temperature rises too fast, residual chlorine may cause the solution to foam and overflow. If this happens, immediately stop stirring and close the steam control valve.