Chlorination gold separation method

Abstract

The invention discloses a chlorination gold separation method which comprises the following steps: starting a sodium chlorate delivery pump, and pumping a sodium chlorate solution with a certain concentration into a head tank for later use; starting a material conveying pump, pumping a gold-containing material and production auxiliary materials into the gold separation reaction tank, and preparing a gold separation reaction system; opening a steam regulating valve, and raising the temperature to 50-55 DEG C; opening a sodium chlorate regulating valve, and controlling the adding amount of sodium chlorate according to the potential value; continuously raising the temperature to 70-75 DEG C, and controlling the reaction endpoint by a potential value; and heating to expel chlorine, cooling and stopping. The method has the beneficial effects that the chlorination gold separation reaction rate is mild, the chlorine utilization rate is high, the reagent dosage is small, and the production cost is saved; the process is accurate and simple, chlorine leakage environmental protection accidents caused by improper manual operation are avoided, the labor intensity is low, and the labor cost can be reduced; the reaction endpoint control is accurate, and the chlorination gold separation reaction effect is improved; the chlorine online detector is interlocked with the DCS control system, so that the environmental protection accident of chlorine leakage is avoided, the multi-tank gold separation reaction can be simultaneously carried out, and high efficiency and safety are realized.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for separating gold by chlorination. Background Art

[0002] Gold is commonly known as gold, an important precious metal. Gold is mainly used in jewelry, electrical, medical and aerospace industries, and is also used as a currency hedging material in investment and finance. In the non-ferrous smelting process, gold coexists in the anode mud in the form of a single substance or compound. The process of extracting gold from anode mud has evolved from the earliest pyrometallurgical process, to the subsequent development of the combined process of metallurgy, the full wet process or the process mainly based on the wet process. The wet process mainly uses chlorination to leach gold from solid gold-containing materials into the liquid phase, and then selects suitable reagents to reduce it to obtain coarse gold powder for refining.

[0003] The traditional chlorination gold separation process is to mix the gold-containing material with industrial water, sulfuric acid, sodium chloride or hydrochloric acid and other production auxiliary materials in a certain proportion, and then add solid sodium chlorate to react at a high temperature. Due to the violent reaction process, the chlorine utilization rate is low, and there are unsafe factors such as chlorine leakage; at the same time, the amount of sodium chlorate reagent is large, and the reaction end point is difficult to control.

[0004] Patent document CN112725633A discloses a negative pressure chlorination gold separation process, which includes adding pure water and concentrated hydrochloric acid to a reactor to prepare a liquid reaction material; uniformly mixing the gold-containing material and sodium chlorate for pretreatment; adding the gold-containing pretreated material after the reactor is heated to carry out a chlorination leaching reaction; and negative pressure chlorine removal and cooling filtration. Compared with the traditional chlorination gold separation process, this process reduces the phenomenon of pipe burst or kettle explosion caused by the increase of pressure in the closed reaction container due to the generation of chlorine when sodium chlorate is added, and improves the safety of the chlorination gold separation process. However, the above process conditions are harsh and the negative pressure requirements are extremely high. There are still problems such as low chlorine utilization, high reagent consumption, and difficult control of the reaction end point.

[0005] Therefore, in the process of chlorination gold separation, how to control the reaction rate, improve the efficiency of chlorine utilization, accurately control the reaction endpoint, avoid chlorine leakage environmental accidents caused by improper manual operation, and achieve efficient and safe production are problems that need to be solved urgently by technical personnel in this field. Summary of the invention

[0006] In view of the above problems, the object of the present invention is to provide a method for gold separation by chlorination with strong production controllability, high chlorine utilization efficiency, precise control of reaction endpoint, and high efficiency and safety.

[0007] The objective of the present invention is achieved through the following technical scheme: a chlorination gold separation method, the method specifically comprises the following steps:

[0008] S1) starting the sodium chlorate delivery pump, pumping a certain concentration of sodium chlorate solution into the header tank for standby use;

[0009] S2) starting the gold-containing material delivery pump, pumping the slurried gold-containing material into the gold separation reaction tank, continuously stirring at a certain rate, and then pumping hydrochloric acid, sulfuric acid, and industrial water into the gold separation reaction tank to obtain a gold separation reaction system;

[0010] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 50-55° C.;

[0011] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a certain flow rate, until the potential value stabilizes at a certain value, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0012] S5) continue heating to a certain temperature, react until the potential value stabilizes at a certain value, and continue reacting for a certain time;

[0013] S6) Continue heating to a certain temperature, and then drive out the chlorine. After completion, close the steam regulating valve and stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 40-45°C, and close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, and filter after clarification.

[0014] Furthermore, the concentration of the sodium chlorate solution in S1) is 20-40 g / L.

[0015] Further, the stirring rate in S2) is 250-300 r / min;

[0016] The amount of hydrochloric acid added is such that the concentration of hydrochloric acid in the reaction system is 70-90 g / L; the amount of sulfuric acid added is such that the concentration of sulfuric acid in the reaction system is 40-60 g / L; and the amount of industrial water added is such that the solid-liquid ratio of the reaction system is 1:4-5.

[0017] Furthermore, the gold-containing material in S2) is a material produced during the wet treatment of anode mud, and the material composition content is: Cu 0.5%~2%wt%, Au 0.3%~2%wt%, Ag 4%~12%wt%, Te2%~10%wt%, Pb 5%~20%wt%, Sn 3%~11%wt%, Pt 20~110g / t, Pd 50~400g / t.

[0018] Furthermore, the flow rate of the sodium chlorate solution in S4) is 4L-6L / min; and the potential value is stabilized at 1000-1050mV.

[0019] Furthermore, the heating temperature in S5) is set to 70-75° C., the potential value is stabilized at 1100-1150 mV, and the reaction time is 1.5-2 h.

[0020] Furthermore, the heating temperature in S6) is 90-95° C., and the chlorine removal time is 1-1.5 h.

[0021] Furthermore, the gold content of the gold-separating slag after treatment by the method is not higher than 30 g / t, and the amount of sodium chlorate used is not higher than 34 kg / t of gold-containing material.

[0022] The method comprises dissolving and diluting the reaction reagent sodium chlorate, slowly adding the sodium chlorate solution at a temperature lower than the normal reaction temperature, slowing down the rate of generating chlorine gas by the reaction of sodium chlorate and acid, and avoiding a large amount of chlorine gas from overflowing without participating in the reaction, resulting in a large amount of reagent consumption and a poor gold separation effect.

[0023] The specific reaction mechanism of the present invention is:

[0024] NaClO 3 +6HCl=3Cl 2 ↑+NaCl+3H 2 O

[0025] 2Au+3Cl 2 + 2HCl=2HAuCl 4

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] (1) Sodium chlorate is dissolved and diluted, and added evenly at a low flow rate under conditions lower than the normal chlorination reaction temperature, which results in a moderate reaction rate, high chlorine utilization rate, low reagent consumption, and reduced production costs;

[0028] (2) The process is precise and simple, which reduces manual operation errors, has low labor intensity, and can reduce labor costs;

[0029] (3) The DCS control system uses the potential of the gold separation reaction system to control the reaction, and the reaction endpoint is accurately controlled, which improves the effect of the chlorination gold separation reaction;

[0030] (4) The DCS control system can realize the simultaneous gold separation reaction in multiple tanks. The chlorine online detector interlocks the DCS control system to avoid environmental accidents caused by chlorine leakage, thus realizing a precise, efficient and safe chlorination gold separation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flowchart of a method for separating gold by chlorination. DETAILED DESCRIPTION

[0032] like Figure 1 As shown, the present invention provides a method for gold separation by chlorination, opening the DCS control interface, and implementing the following steps on the DCS system:

[0033] S1) starting the sodium chlorate delivery pump to pump a sodium chlorate solution with a concentration of 20-40 g / L into a high-level tank for standby use;

[0034] S2) starting the gold-containing material delivery pump to pump the slurried gold-containing material into the gold separation reaction tank; starting the reducer of the gold separation reaction tank to control the stirring rate to 250-300r / min; starting the hydrochloric acid delivery pump, the sulfuric acid delivery pump, and the industrial water delivery pump to pump hydrochloric acid, sulfuric acid, and industrial water into the gold separation reaction tank to obtain a gold separation reaction system;

[0035] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 50-55° C.;

[0036] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the high-level tank to the gold separation reaction tank at a flow rate of 4L-6L / min, until the potential value stabilizes at 1000-1050mV, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0037] S5) setting and heating the reaction system temperature to 70-75° C., reacting until the potential value stabilizes at 1100-1150 mV, and continuing the reaction for 1.5-2 h;

[0038] S6) Set and heat the reaction system temperature to 90-95°C, drive out chlorine for 1-1.5 hours, close the steam regulating valve, and stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 40-45°C, and close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, clarify and filter.

[0039] According to the embodiment of the present disclosure, the bottom of the high-level tank in S1) is 1 to 2 meters higher than the top of the gold separation reaction tank in S2).

[0040] According to the embodiment of the present disclosure, the diameter of the connecting pipe between the high-level tank in S1) and the gold separation reaction tank in S2) is 10mm-20mm, and the connecting pipe is installed with a flow meter matching the pipe diameter.

[0041] According to the embodiment of the present disclosure, the amount of hydrochloric acid added in S2) is such that the concentration of hydrochloric acid in the reaction system is 70 to 90 g / L; the amount of sulfuric acid added is such that the concentration of sulfuric acid in the reaction system is 40 to 60 g / L; the amount of industrial water added is such that the solid-liquid ratio of the reaction system is 1:4 to 5;

[0042] According to the embodiment of the present disclosure, the gold separation reaction tank in S2) is equipped with a thermometer, a potentiometer, and a chlorine online detector; the tail gas of the gold separation reaction tank is extracted by an induced draft fan and introduced into a chlorine spray absorption tower.

[0043] According to the embodiment of the present disclosure, in the S4) process, when the detection value of the chlorine online detector exceeds 80% to 90% of the emission upper limit, the DCS control system interlocks and controls to close the sodium chlorate regulating valve and stop adding the sodium chlorate solution.

[0044] According to the embodiment of the present disclosure, when the detection value of the chlorine gas detector is lower than 30% to 40% of the upper emission limit, the DCS control system resumes the original set control program.

[0045] According to the embodiment of the present disclosure, the DCS control system can control multiple tanks of gold separation reactions to proceed simultaneously.

[0046] The gold-containing materials to be treated in the following Examples 1-4 and Comparative Examples 1-2 are produced by the wet treatment process of anode mud, and the contents of the main components are: Cu 1.29wt%, Au 1.68wt%, Ag 8.57wt%, Te3.48wt%, Pb 14.57wt%, Sn 8.45wt%, Pt 65g / t, and Pd 224g / t.

[0047] Embodiment 1:

[0048] A method for separating gold by chlorination, opening a DCS control interface, and implementing the following steps on the DCS system:

[0049] S1) start the sodium chlorate delivery pump, and the sodium chlorate solution that concentration is 20g / L is pumped into the header tank for standby;

[0050] S2) Start the gold-containing material delivery pump to pump the slurried gold-containing material into the gold separation reaction tank; start the gold separation reaction tank reducer to control the stirring rate to 250r / min; start the hydrochloric acid delivery pump, sulfuric acid delivery pump, and industrial water delivery pump to pump hydrochloric acid, sulfuric acid, and industrial water to control the solid-liquid ratio of the reaction system to 1:4, the hydrochloric acid concentration to 70g / L, and the sulfuric acid concentration to 60g / L;

[0051] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 55°C;

[0052] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a flow rate of 6L / min until the potential value stabilizes at 1000mV, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0053] S5) setting and heating the reaction system temperature to 70° C., reacting until the potential value stabilizes at 1100 mV, and continuing the reaction for 2 h;

[0054] S6) Set and heat the reaction system temperature to 95°C, drive out chlorine for 1 hour, close the steam regulating valve, stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 45°C, close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, clarify and filter. After analysis, the gold content of the gold separation slag is 30g / t, and the amount of sodium chlorate is 29kg / t of gold-containing material.

[0055] Embodiment 2:

[0056] A method for separating gold by chlorination, opening a DCS control interface, and implementing the following steps on the DCS system:

[0057] S1) start the sodium chlorate delivery pump, and the sodium chlorate solution that concentration is 40g / L is pumped into the header tank for standby;

[0058] S2) Start the gold-containing material delivery pump to pump the slurried gold-containing material into the gold separation reaction tank; start the gold separation reaction tank reducer to control the stirring rate to 250r / min; start the hydrochloric acid delivery pump, sulfuric acid delivery pump, and industrial water delivery pump to pump hydrochloric acid, sulfuric acid, and industrial water to control the solid-liquid ratio of the reaction system to 1:4.5, the hydrochloric acid concentration to 80g / L, and the sulfuric acid concentration to 50g / L;

[0059] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 55°C;

[0060] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a flow rate of 4L / min until the potential value stabilizes at 1000mV, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0061] S5) setting and heating the reaction system temperature to 70° C., reacting until the potential value stabilizes at 1100 mV, and continuing the reaction for 2 h;

[0062] S6) Set and heat the reaction system temperature to 95°C, drive out chlorine for 1 hour, close the steam regulating valve, stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 40°C, close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, clarify and filter. After analysis, the gold content of the gold separation slag is 25g / t, and the amount of sodium chlorate is 31kg / t of gold-containing material.

[0063] Embodiment 3:

[0064] A method for separating gold by chlorination, opening a DCS control interface, and implementing the following steps on the DCS system:

[0065] S1) start the sodium chlorate delivery pump, and the sodium chlorate solution that concentration is 30g / L is pumped into the header tank for standby;

[0066] S2) Start the gold-containing material delivery pump to pump the slurried gold-containing material into the gold separation reaction tank; start the gold separation reaction tank reducer to control the stirring rate to 300r / min; start the hydrochloric acid delivery pump, sulfuric acid delivery pump, and industrial water delivery pump to pump hydrochloric acid, sulfuric acid, and industrial water to control the solid-liquid ratio of the reaction system to 1:4.5, the hydrochloric acid concentration to 90g / L, and the sulfuric acid concentration to 40g / L;

[0067] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 50°C;

[0068] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a flow rate of 5L / min until the potential value stabilizes at 1050mV, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0069] S5) setting and heating the reaction system temperature to 75° C., reacting until the potential value stabilizes at 1150 mV, and continuing the reaction for 1.5 h;

[0070] S6) Set and heat the reaction system temperature to 90°C, drive out chlorine for 1.5 hours, close the steam regulating valve, stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 45°C, close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, clarify and filter. After analysis, the gold content of the gold separation slag is 26g / t, and the amount of sodium chlorate is 32kg / t of gold-containing material.

[0071] Embodiment 4:

[0072] A method for separating gold by chlorination, opening a DCS control interface, and implementing the following steps on the DCS system:

[0073] S1) start the sodium chlorate delivery pump, and the sodium chlorate solution that concentration is 30g / L is pumped into the header tank for standby;

[0074] S2) Start the gold-containing material delivery pump to pump the slurried gold-containing material into the gold separation reaction tank; start the gold separation reaction tank reducer to control the stirring rate to 300r / min; start the hydrochloric acid delivery pump, sulfuric acid delivery pump, and industrial water delivery pump to pump hydrochloric acid, sulfuric acid, and industrial water to control the solid-liquid ratio of the reaction system to 1:5, the hydrochloric acid concentration to 80g / L, and the sulfuric acid concentration to 50g / L;

[0075] S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 50°C;

[0076] S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a flow rate of 4L / min until the potential value stabilizes at 1050mV, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution;

[0077] S5) setting and heating the reaction system temperature to 75° C., reacting until the potential value stabilizes at 1150 mV, and continuing the reaction for 1.5 h;

[0078] S6) Set and heat the reaction system temperature to 90°C, drive out chlorine for 1.5 hours, close the steam regulating valve, stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 40°C, close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, clarify and filter. After analysis, the gold content of the gold separation slag is 22g / t, and the amount of sodium chlorate is 34kg / t of gold-containing material.

[0079] Comparative Example 1:

[0080] The method for gold separation by chlorination in this comparative example comprises the following steps:

[0081] S1) preparing a gold separation reaction system: pump the slurried gold-containing material into a gold separation reaction tank, add hydrochloric acid, sulfuric acid and industrial water to control the solid-liquid ratio of the reaction system to 1:4, the concentration of hydrochloric acid is 80g / L, the concentration of sulfuric acid is 50g / L, and the stirring is continued at a speed of 300r / min;

[0082] S2) Chlorination gold separation: Steam is introduced into the coil of the gold separation reaction tank to heat it to 70°C, solid sodium chlorate is added according to the ratio of gold content in the gold-containing material to sodium chlorate of 1:7, and the reaction is carried out for 2 hours, and the potential value is 1024mv;

[0083] S3) Chlorine removal and cooling: Raise the temperature of the reaction system to 95°C and remove chlorine for 1.5 hours; then introduce circulating water into the gold separation reaction tank coil to cool to 40°C, and stop the machine for clarification and filtration. After analysis, the gold content of the gold separation slag is 162g / t, and the amount of sodium chlorate used is 54kg / t of gold-containing material.

[0084] Comparative Example 2:

[0085] The method for gold separation by chlorination in this comparative example comprises the following steps:

[0086] S1) preparing a gold separation reaction system: pump the slurried gold-containing material into a gold separation reaction tank, add hydrochloric acid, sulfuric acid and industrial water to control the solid-liquid ratio of the reaction system to 1:5, the concentration of hydrochloric acid is 90g / L, the concentration of sulfuric acid is 60g / L, and the stirring is continued at a speed of 250r / min;

[0087] S2) Chlorination gold separation: Steam is introduced into the coil of the gold separation reaction tank to heat it to 75°C, solid sodium chlorate is added according to the ratio of gold content in the gold-containing material to sodium chlorate of 1:8, and the reaction is carried out for 2 hours, and the potential value is 1036mv;

[0088] S3) Chlorine removal and cooling: Raise the temperature of the reaction system to 95°C and remove chlorine for 1.5 hours; then introduce circulating water into the gold separation reaction tank coil to cool to 40°C, and stop the machine for clarification and filtration. After analysis, the gold content of the gold separation slag is 153g / t, and the amount of sodium chlorate used is 58kg / t of gold-containing material.

[0089] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for separating gold by chlorination, characterized in that: The method specifically comprises the following steps: S1) starting the sodium chlorate delivery pump, pumping a certain concentration of sodium chlorate solution into the header tank for standby use; S2) starting the gold-containing material delivery pump, pumping the slurried gold-containing material into the gold separation reaction tank, continuously stirring at a certain rate, and then pumping hydrochloric acid, sulfuric acid, and industrial water into the gold separation reaction tank to obtain a gold separation reaction system; S3) Open the steam regulating valve of the gold separation reaction tank coil, set and heat the reaction system temperature to 50-55° C.; S4) opening the sodium chlorate regulating valve, adding the sodium chlorate solution in the header tank to the gold separation reaction tank at a certain flow rate, until the potential value stabilizes at a certain value, closing the sodium chlorate regulating valve, and stopping adding the sodium chlorate solution; S5) continue heating to a certain temperature, react until the potential value stabilizes at a certain value, and continue reacting for a certain time; S6) Continue heating to a certain temperature, and then drive out the chlorine. After completion, close the steam regulating valve and stop heating; open the pneumatic valve of the circulating water of the gold separation reaction tank coil, cool to 40-45°C, and close the pneumatic valve of the circulating water; stop the reducer of the gold separation reaction tank, and filter after clarification.

2. The method according to claim 1, characterized in that: The concentration of the sodium chlorate solution in S1) is 20-40 g / L.

3. The method according to claim 1, characterized in that The stirring rate in S2) is 250-300 r / min; the amount of hydrochloric acid added is such that the concentration of hydrochloric acid in the reaction system is 70-90 g / L; the amount of sulfuric acid added is such that the concentration of sulfuric acid in the reaction system is 40-60 g / L; and the amount of industrial water added is such that the solid-liquid ratio of the reaction system is 1:4-5.

4. The method according to claim 1, characterized in that: The gold-containing material in S2) is produced during the wet treatment of anode mud, and the material composition content is: Cu 0.5%~2%wt%, Au 0.3%~2%wt%, Ag 4%~12%wt%, Te 2%~10%wt%, Pb 5%~20%wt%, Sn3%~11%wt%, Pt 20~110g / t, Pd50~400g / t.

5. The method according to claim 1, characterized in that The flow rate of the sodium chlorate solution in S4) is 4L-6L / min; the potential value is stabilized at 1000-1050mV.

6. The method according to claim 1, characterized in that The heating temperature in S5) is 70-75°C, the potential value is stabilized at 1100-1150 mV, and the reaction time is 1.5-2 hours.

7. The method according to claim 1, characterized in that The heating temperature in said S6) is 90-95°C, and the chlorine removal time is 1-1.5h.

8. The method according to claim 1, characterized in that The gold content of the gold-separating slag after treatment by the method is not higher than 30 g / t, and the amount of sodium chlorate used is not higher than 34 kg / t of gold-containing material.

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