Process and system for extracting gold from pregnant solution through quality-divided and flow-divided dynamic circulation cascade adsorption

Abstract

The invention relates to a pregnant solution quality-dividing and flow-dividing dynamic circulation cascade adsorption gold extraction process and a system thereof, and the process comprises the following steps: carrying out quality-dividing and flow-dividing on a pregnant solution, and dividing the pregnant solution into three grades of high grade, medium grade and low grade; calcium ion targeted inhibition synergistic scale inhibition treatment is carried out, and a polyaspartic acid, sodium citrate and carboxymethyl chitosan composite reagent is added into different grades of pregnant solutions, so that free calcium ions in the pregnant solutions form a soluble stable complex, and scaling is prevented; according to cross-group dynamic carbon circulation gradient adsorption, pregnant solutions of different grades are transferred into corresponding adsorption tower groups at different flow speeds to be subjected to activated carbon adsorption, cross-group scheduling circulation of gold-loaded carbon is performed in the adsorption process, the adsorption efficiency is improved, and the adsorption period is shortened. The system comprises a plurality of heap leaching fields, and each heap leaching field is connected with a first pregnant solution pipe, a second pregnant solution pipe and a third pregnant solution pipe. According to the method, the recovery rate of gold in the pregnant solution is remarkably increased, the adsorption efficiency is optimized, and an efficient, economical and environment-friendly solution is provided for the heap leaching gold extraction process.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgy, and in particular relates to a precious liquid fractionation and diversion dynamic circulation cascade adsorption gold extraction process and a system thereof. Background Art

[0002] In the heap leaching process, after the gold-bearing ore is leached, the precious liquid is typically adsorbed with activated carbon to recover the gold. However, existing processes present numerous problems, particularly the significant variation in the grade of the precious liquid in the heap during different spray cycles. Typically, the grade is high in the early stages, gradually decreasing in the middle stages, and lower in the later stages, when the heap is primarily washed. The current process involves concentrating the precious liquid from various heaps into a single precious liquid pool, where it is then adsorbed with activated carbon. This mixed, centralized adsorption method presents the following disadvantages: (1) Dilution of high-grade solution: Due to the large differences in the grade of precious solution in different leaching cycles at different storage sites, the high-grade solution will be diluted by the low-grade solution after mixing, resulting in a lower grade. The activated carbon adsorption rate is positively correlated with the initial concentration gradient of the solution, which leads to a decrease in the adsorption efficiency of the activated carbon and a longer adsorption cycle. Currently, the grade of gold-loaded carbon is about 2000-3000g / t, and the adsorption cycle is 20-30 days.

[0003] (2) The gold analysis recovery rate is reduced: Due to the low grade of gold-loaded carbon, the gold analysis recovery rate is reduced and the analysis cost is increased.

[0004] (3) Serious calcification: A certain amount of lime must be added to the storage yard, resulting in a high calcium content in the precious liquid. Direct adsorption of precious liquid often leads to severe calcification of the activated carbon in the tower, carbon compaction, and reduced carbon adsorption efficiency. In addition, the continued use of the adsorbed lean liquid for spraying in the storage yard often leads to calcium deposition in the spray pipes and nozzles, reducing spray efficiency and requiring frequent nozzle replacement.

[0005] In response to the above problems, the present invention proposes a precious liquid fractionation and diversion dynamic circulation cascade adsorption gold extraction process and system. The main purpose is to improve the adsorption method of the precious liquid, solve the influence of calcium ions in the precious liquid, optimize the adsorption method of the adsorption tower on the gold-loaded carbon, thereby improving the adsorption efficiency and the grade of the gold-loaded carbon, shortening the adsorption cycle, improving the spraying efficiency, and reducing the frequency of replacing nozzles and pipelines. Summary of the Invention

[0006] The present invention provides a precious liquid quality separation and diversion dynamic circulation cascade adsorption gold extraction process and a system thereof.

[0007] The specific technical solution is: A noble liquid fractionation and diversion dynamic cycle cascade adsorption gold extraction process comprises the following steps: S1. Precious liquid separation and diversion: During the heap leaching process, the grade of the precious liquid in the heap is tested and the precious liquid is separated into high, medium and low grades according to the grade, and then drained into different stirring tanks respectively; This step divides the heap leaching precious liquid into high-grade (>1.5g / m 3 ), medium grade (0.5~1.5g / m 3 ), low grade (﹤0.5g / m 3 ) three, which is conducive to subsequent targeted adsorption recovery, improves the overall adsorption efficiency, and shortens the adsorption cycle. At the same time, due to the different content of calcium ions in the precious liquid during different spraying periods, the precious liquids with similar calcium ion content can be gathered together after separation and diversion, making the subsequent calcium ion targeted inhibition and synergistic scale inhibition treatment more targeted, and also avoiding the high content of impurity ions (such as Fe 3+ 、Cu 2+ ) interferes with the adsorption process of high-grade precious liquid.

[0008] S2. Calcium ion targeted inhibition and synergistic scale inhibition treatment: The calcium ion concentration in high-, medium-, and low-grade precious liquids is tested, and corresponding amounts of a composite scale inhibitor consisting of polyaspartic acid, sodium citrate, and carboxymethyl chitosan are added according to the calcium ion concentration to form soluble stable complexes of the free calcium ions in each precious liquid to prevent scaling. During the heap leaching process, the pH of the precious liquid is adjusted by adding lime (usually maintaining a pH of 10-11 to stabilize the gold-cyanide complex), resulting in a Ca²⁺ concentration in the solution as high as 1000-1200 mg / L. Calcium ions combine with CO²⁻ in the solution to form CaCO³ precipitates. Once in the adsorption tower, CaCO³ tends to deposit on the surface of the activated carbon and the inner walls of the pipes, leading to calcification of the activated carbon and scaling of the pipes. Therefore, before the precious liquid enters the adsorption process, it is necessary to prioritize the formation of other soluble, stable complexes by free calcium ions to prevent the formation of CaCO³ and other deposits that form scaling. Specifically, this involves the use of a ternary synergistic scale inhibition technology called "chelation-dispersion-lattice distortion": (1) Chelation (polyaspartic acid): The carboxylic acid group (-COOH) on the polyaspartic acid molecular chain forms a stable complex with Ca²⁺ (complexation constant logK=8.2), reducing the free Ca²⁺ concentration to <50 mg / L and inhibiting CaCO3 nucleation.

[0009] (2) Dispersion effect (sodium citrate): Sodium citrate disperses the microcrystalline particles through electrostatic repulsion (Zeta potential drops from +5 mV to -25 mV), preventing them from aggregating and growing (particle size < 50 nm) and avoiding deposition.

[0010] (3) Lattice distortion (carboxymethyl chitosan): Carboxymethyl chitosan (degree of substitution ≥ 80%) is adsorbed on the surface of CaCO3 crystal nuclei, interfering with the directional growth of the crystals and causing the crystal structure to change from dense calcite (density 2.71-2.83 g / cm³) to loose aragonite (density 2.93-2.95 g / cm³), which is easily dispersed by liquid flow and prevents deposition.

[0011] This ternary synergistic scale inhibition technology combines polyaspartic acid, sodium citrate and carboxymethyl chitosan, breaking through the efficiency bottleneck of traditional single agents. It has a high scale inhibition rate and, combined with the grade classification of precious liquid, can specifically adjust the amount of scale inhibition agent added to ensure that calcium ion scaling is effectively inhibited with low agent consumption, solving the impact of calcium ions on adsorption and spraying systems.

[0012] S3. Dynamic carbon circulation gradient adsorption across groups: The high-grade, medium-grade and low-grade precious liquids treated with composite scale inhibitors are transferred to the corresponding adsorption tower groups (i.e., high-grade adsorption tower group, medium-grade adsorption tower group and low-grade adsorption tower group) at different adsorption flow rates for activated carbon adsorption. Each adsorption tower group consists of multiple adsorption towers connected in series. As the adsorption operation proceeds, the activated carbon grade in each adsorption tower group presents a gradient distribution from high to low according to the direction of liquid flow. In this process, it is necessary to carry out cross-group scheduling and circulation of gold-loaded carbon. Specifically, when the gold-loaded carbon in the high-grade adsorption tower group reaches the saturation threshold (≥8kg / t), the saturated carbon is unloaded, and then the carbon with relatively high gold-loaded carbon grade in the medium-grade adsorption tower group is transferred to the high-grade adsorption tower group, and then the carbon with relatively high gold-loaded carbon grade in the low-grade adsorption tower group is transferred to the medium-grade adsorption tower group. Finally, the new carbon or regenerated carbon is transferred to the high-grade adsorption tower group. Carbon is added to the low-grade adsorption tower group, and the entire scheduling cycle operation always follows the principle of "the grade of gold-loaded carbon in each group of adsorption towers is distributed in a gradient from high to low along the direction of liquid flow"; this is repeated, and the high-grade precious liquid always contacts the high-grade gold-loaded carbon, the gold-loaded carbon is quickly saturated, and the remaining gold ions are forced to migrate to the low-grade gold-loaded carbon, forming a directional concentration difference driving force, achieving the effect of precise matching of grade and adsorption energy efficiency, shortening the adsorption equilibrium time, and increasing the overall adsorption rate; finally, the residual lean liquid after activated carbon adsorption can be reused for yard spraying.

[0013] This step optimizes the adsorption flow rate of different grades of precious liquid based on the different adsorption behaviors of high, medium and low grade precious liquids to ensure the adsorption effect and efficiency. The details are as follows: High-grade precious liquid is rapidly passed through the adsorption tower at a high flow rate (25m³ / h). Utilizing the remaining adsorption sites of the highly gold-loaded carbon, the adsorption of the main amount of gold is completed within a short contact time (adsorption rate constant k=0.48 min⁻¹), avoiding the prolonged retention of high-concentration gold ions in the tower that would lead to local saturation of the carbon surface (the mass transfer boundary layer thickness is reduced by 50% at high flow rates, improving the diffusion rate).

[0014] Medium-grade precious liquid uses a moderate flow rate (17 m³ / h) to extend the liquid-carbon contact time (up to 25% at higher rates), ensuring that the medium-concentration gold ions fully migrate into the carbon pores. This flow rate matches the adsorption capacity of the medium-grade carbon for gold loading, balancing efficiency and adsorption depth.

[0015] Low-grade precious liquid runs at a low flow rate (10m³ / h). By extending the residence time (60% increase at a higher rate), low-concentration gold ions are fully adsorbed on the gold-loaded carbon, overcoming the problem of insufficient diffusion driving force at low concentrations.

[0016] The adsorption operation is carried out in steps according to different adsorption flow rates and gold-loaded carbon grades from high to low.

[0017] This step adopts the coupling mechanism of "gradient adsorption-gold-loaded carbon cross-group scheduling cycle" to realize the cross-group circulation of carbon resources and the reconstruction of adsorption gradient, forming a multi-dimensional synergistic efficiency mechanism, breaking through the limitations of the traditional adsorption tower's independent operation, so that the high-grade precious liquid is always in contact with the high-gold-loaded carbon (tower 1), and the high-concentration gold is quickly adsorbed by the high-gold-loaded carbon to reach a saturation state, while the remaining gold ions continue to migrate to the low-gold-loaded carbon, forming a directional concentration difference driving force, achieving the effect of precise matching of grade and adsorption energy efficiency, shortening the adsorption equilibrium time, improving the overall adsorption rate, and shortening the adsorption cycle.

[0018] Furthermore, the grades of high-grade, medium-grade and low-grade precious liquids in step S1 (i.e., the gold content in the precious liquid) are greater than 1.5 g / m 3 , 0.5~1.5g / m 3 Less than 0.5g / m 3 .

[0019] Furthermore, the addition amount of the composite scale inhibitor in step S2 is calculated based on the unit consumption of calcium ions. If the calcium ion concentration in the precious solution is less than 300 mg / L, polyaspartic acid, sodium citrate carboxyl and methyl chitosan are added at a unit consumption of 1.5 mg / mg, 0.4 mg / mg and 0.1 mg / mg, respectively; if the calcium ion concentration in the precious solution is greater than 300 mg / L, polyaspartic acid, sodium citrate carboxyl and methyl chitosan are added at a unit consumption of 1.8 mg / mg, 0.5 mg / mg and 0.2 mg / mg, respectively.

[0020] Furthermore, in step S3, the adsorption flow rates of the high-grade, medium-grade, and low-grade noble liquids are 25 m³ / h, 17 m³ / h, and 10 m³ / h, respectively.

[0021] The present invention also provides a system for the above-mentioned noble liquid fractionation and diversion dynamic circulation cascade adsorption gold extraction process, comprising multiple heap leaching sites, each of which is connected to a 1# noble liquid pipe, a 2# noble liquid pipe and a 3# noble liquid pipe, all of which are equipped with valves, all of which are connected to a 1# stirring tank, all of which are connected to a 2# stirring tank, and all of which are connected to a 3# stirring tank. The 1# stirring tank, the 2# stirring tank and the 3# stirring tank are respectively connected to the 1# noble liquid pool, the 2# noble liquid pool and the 3# noble liquid pool through gravity pipes, and the 1# noble liquid pool, the 2# noble liquid pool and the 3# noble liquid pool are respectively connected to the 1# adsorption tower group, the 2# adsorption tower group and the 3# adsorption tower group through delivery pipes and delivery pumps, and flow meters are installed on the delivery pipes.

[0022] Furthermore, the 1# adsorption tower group, the 2# adsorption tower group and / or the 3# adsorption tower group are each composed of five adsorption towers connected in series.

[0023] Beneficial effects of the present invention: Through the multi-dimensional synergistic efficiency enhancement technology of "precious liquid separation and diversion - calcium ion targeted inhibition and synergistic scale inhibition - cross-group dynamic carbon circulation gradient adsorption", the present invention overcomes the long-standing problems of grade dilution, calcium deposition, and low carbon adsorption efficiency in the field of heap leaching precious liquid adsorption, achieving a synergistic improvement in gold recovery, economic benefits, and environmental benefits. This is specifically reflected in the following aspects: (1) Optimizing adsorption efficiency: By implementing quality-separated and diverted adsorption of precious liquid, a precise match between concentration and adsorption energy efficiency is achieved, avoiding the problems of dilution of high-grade precious liquid and insufficient adsorption of low-grade precious liquid. At the same time, through the gradient utilization of carbon resources and precise process control, the adsorption kinetics are optimized, improving the overall adsorption efficiency.

[0024] (2) Reduce the impact of calcium ions: Through the "chelation-dispersion-lattice distortion" multi-mechanism ternary synergistic scale inhibition technology, polyaspartic acid, sodium citrate, and carboxymethyl chitosan are combined to break through the efficiency bottleneck of traditional single agents, improve the scale inhibition rate, and effectively solve the impact of calcium ions on the adsorption and spraying systems, reducing the calcification and scaling of activated carbon and the problem of pipeline scaling.

[0025] (3) Improving the grade of gold-loaded carbon: Through the coupling mechanism of "gradient adsorption-cross-group circulation", cross-group circulation of carbon resources and reconstruction of adsorption gradient are achieved, breaking through the limitations of traditional adsorption towers operating independently. High-grade noble liquid is always in contact with high-grade gold-loaded carbon. High-concentration gold is quickly adsorbed to saturation, and the remaining gold ions migrate to the low-grade gold-loaded carbon, forming a directional concentration difference driving force, shortening the adsorption equilibrium time, improving the overall adsorption rate, and shortening the adsorption cycle.

[0026] (4) Resource recycling: Through dynamic carbon recycling across groups, resource recycling and upgrading of gold-loaded carbon are achieved, the comprehensive gold loading capacity of carbon is increased, and energy consumption, reagents and maintenance costs are reduced. At the same time, the barren liquid after adsorption can be reused for yard spraying, realizing resource recycling and reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of a noble liquid fractionation and diversion dynamic cycle cascade adsorption gold extraction process of the present invention; Figure 2 This is an equipment association diagram of a precious liquid fractionation and diversion dynamic circulation cascade adsorption gold extraction process system of the present invention; In the figure: 1- heap leaching site; 21- 1# precious liquid pipe, 22- 2# precious liquid pipe, 23- 3# precious liquid pipe; 31- 1# stirring tank, 32- 2# stirring tank, 33- 3# stirring tank; 41- 1# precious liquid pool, 42- 2# precious liquid pool, 43- 3# precious liquid pool; 51- 1# adsorption tower group, 52- 2# adsorption tower group, 53- 3# adsorption tower group; 6- gravity pipe; 7- delivery pipe; 8- delivery pump; 9- flow meter. DETAILED DESCRIPTION

[0028] In order to make the technical problems and technical solutions solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0029] For a certain mine's No. 1-3 heap leaching sites, No. 1 is in the initial spraying stage, with a precious liquid grade of 2.0g / m³ and a calcium ion concentration of 1100mg / L; No. 2 is in the middle spraying stage, with a precious liquid grade of 1.2g / m³ and a calcium ion concentration of 700mg / L; No. 3 is in the late spraying stage, with a precious liquid grade of 0.3g / m³ and a calcium ion concentration of 200mg / L. Using traditional processing technology, the average grade of the precious liquid after mixing is only 0.96g / m³, and the grade of gold-loaded carbon after adsorption is 2100g / t. The process faces problems such as precious liquid grade dilution, calcification and compaction of activated carbon, and a long adsorption cycle (approximately 25 days).

[0030] like Figure 1 As shown, the process of the present invention is used to treat the above-mentioned precious liquid, including the following steps: S1. Precious liquid separation and diversion: During the heap leaching process, the grade of the precious liquid in the heap is tested and divided into high, medium and low grade precious liquids according to the grade of the precious liquid, and the liquids are respectively diverted to different stirring tanks; the grade of the collected high-grade precious liquid is 2g / m 3 The grade of medium-grade precious liquid is 1.2g / m 3 , the grade of low-grade precious liquid is 0.3g / m3 .

[0031] S2. Calcium ion targeted inhibition and synergistic scale inhibition: The calcium ion concentrations in the high, medium and low grade precious liquids were detected to be 1100 mg / L, 700 mg / L and 200 mg / L respectively. According to the calcium ion concentration, polyaspartic acid, sodium citrate carboxyl and methyl chitosan were added to high-grade and medium-grade precious liquids at a unit consumption of 1.8 mg / mg, 0.5 mg / mg and 0.2 mg / mg respectively; polyaspartic acid, sodium citrate carboxyl and methyl chitosan were added to low-grade precious liquid at a unit consumption of 1.5 mg / mg, 0.4 mg / mg and 0.1 mg / mg respectively; after the addition was completed, the mixture was stirred for 30 minutes to allow the free calcium ions to fully react and form a soluble stable complex; at this time, the concentrations of free calcium ions in high-, medium- and low-grade precious liquids were 45 mg / L, 36 mg / L and 12 mg / L respectively, which reduced the amount of CaCO3 and other precipitations by more than 94% compared with the traditional process, effectively inhibiting the formation of scaling, and significantly reducing the risk of activated carbon and pipeline calcification.

[0032] S3. Cross-group dynamic carbon circulation gradient adsorption: After treatment with a composite scale inhibitor, high-, medium-, and low-grade precious liquids are transferred to corresponding adsorption tower groups (i.e., high-grade adsorption tower group A1-A5, medium-grade adsorption tower group B1-B5, and low-grade adsorption tower group C1-C5) at different adsorption flow rates for activated carbon adsorption. Each group consists of five adsorption towers connected in series. High-grade precious liquid flows through the adsorption towers at a flow rate of 25 m³ / h, medium-grade precious liquid at a flow rate of 17 m³ / h, and low-grade precious liquid at a flow rate of 10 m³ / h.

[0033] As the adsorption operation progresses, the grade of activated carbon in each adsorption tower group presents a gradient distribution from high to low according to the direction of liquid flow. During this process, by detecting the grade of gold-loaded carbon, after 10 days of adsorption, the gold loading of carbon in tower A1 of the high-grade adsorption tower group reaches the saturation threshold (≥8kg / t), and the saturated carbon in tower A1 is immediately unloaded. Then, scheduling adjustments are made according to the grade of the remaining gold-loaded carbon in each group, that is, A2→A1, A3→A2, B1→A3 form a high-grade adsorption tower group, B2→B1, B3→B2, C1→B3 form a medium-grade adsorption tower group, and C2→C1, C3→C2, C4→C3, C5→C4, C5 are loaded with new carbon or lean carbon to form a low-grade adsorption group. The dynamic scheduling of gold-loaded carbon across groups is carried out in this cycle, and the entire scheduling cycle operation always follows the principle of "the grade of gold-loaded carbon in each group of adsorption towers is distributed in a gradient from high to low according to the direction of liquid flow" until all the precious liquid to be treated is adsorbed.

[0034] The method of the present invention adopts the "quality separation and diversion - calcium ion targeted inhibition and synergistic scale inhibition - cross-group dynamic carbon circulation gradient adsorption" process technology, which can effectively inhibit the formation of scale and greatly reduce the impact of calcium ions on adsorption and spraying operations. In addition, by controlling the adsorption flow rate of different grades of precious liquid and the grade of gold-loaded carbon, the adsorption efficiency of activated carbon is greatly improved. The actual process indicators improved are as follows: (1) Increased gold loading and reduced carbon consumption: The grade of gold-loaded carbon increased from 2000-3000 g / t to over 8000 g / t, and the grade of gold-loaded carbon increased by 266%-400%. Through dynamic carbon circulation scheduling, the overall adsorption rate constant increased by 37% (from 0.35 to 0.48 min -1 ), the carbon reuse rate reaches 92% (traditional process ≤ 75%), the carbon cycle times increase from 3-5 times to 8-10 times, and the carbon replacement cost is reduced by 50%.

[0035] (2) Shortened adsorption cycle: The activated carbon adsorption cycle is reduced from the original 20-30 days to 10 days, which is about 50%-70% shorter, greatly improving production efficiency.

[0036] (3) Improved scale inhibition efficiency: free Ca in the solution ²+ The concentration dropped from 1000-1200 mg / L to less than 50 mg / L, and free Ca ²+ The concentration was reduced by more than 94%. The scaling rate of activated carbon, pipes and nozzles was greatly reduced, which greatly improved the efficiency of spraying and reduced the frequent replacement and maintenance of nozzles.

[0037] (4) The cost of gold-loaded carbon analysis is reduced, and the comprehensive gold recovery rate is improved. After the grade of gold-loaded carbon is improved, the comprehensive cost of gold analysis is reduced by about 65%, and the comprehensive gold recovery rate is increased by about 1.2%. Example 2

[0038] like Figure 2As shown, this embodiment provides a system for the above-mentioned noble liquid separation and diversion dynamic circulation cascade adsorption gold extraction process, including multiple heap leaching sites 1, each of which is connected to a 1# noble liquid pipe 21, a 2# noble liquid pipe 22, and a 3# noble liquid pipe 23. Valves are installed on all 1# noble liquid pipes 21, 2# noble liquid pipes 22, and 3# noble liquid pipes 23. All 1# noble liquid pipes 21 are connected to a 1# stirring tank 31, all 2# noble liquid pipes 22 are connected to a 2# stirring tank 32, and all The 3# noble liquid pipes 23 are all connected to the 3# stirring tank 33. The 1# stirring tank 31, the 2# stirring tank 32, and the 3# stirring tank 33 are respectively connected to the 1# noble liquid pool 41, the 2# noble liquid pool 42, and the 3# noble liquid pool 43 via gravity pipes 6. The 1# noble liquid pool 41, the 2# noble liquid pool 42, and the 3# noble liquid pool 43 are respectively connected to the 1# adsorption tower group 51, the 2# adsorption tower group 52, and the 3# adsorption tower group 53 via delivery pipes 7 and delivery pumps 8. Flow meters 9 are installed on the delivery pipes 7. The 1# adsorption tower group 51, the 2# adsorption tower group 52, and / or the 3# adsorption tower group 53 are each composed of five adsorption towers connected in series.

[0039] Among them, the volume of 1# precious liquid pool 41, 2# precious liquid pool 42 and 3# precious liquid pool 43 is 300m 3 The dimensions of the 1# agitation tank 31, 2# agitation tank 32, and 3# agitation tank 33 are Ø4×4m; the height of the adsorption tower is Ø1×3m. Of course, the dimensions of the above equipment are not limited to Yuci and can be adjusted according to actual needs.

[0040] It should also be noted that the equipment involved in this implementation are all existing equipment. This implementation only involves the application of these equipment and does not involve structural modification of the equipment.

[0041] When using this system to treat precious liquid in heap leaching, the grade of precious liquid should be checked in time during the heap leaching process. The grade of precious liquid should be > 1.5g / m 3 When the precious liquid is at a high grade, close the valves on the 2# precious liquid pipe 22 and the 3# precious liquid pipe 23 to allow the high-grade precious liquid to flow from the 1# precious liquid pipe 21 to the 1# stirring tank 31. If the precious liquid grade is between 0.5 and 1.5 g / m 3 Close the valves on the 1# noble liquid pipe 21 and the 3# noble liquid pipe 23, and let the medium-grade noble liquid flow from the 2# noble liquid pipe 22 to the 2# stirring tank 32; if the noble liquid grade is less than 0.5g / m 3 , close the valves on the 1# noble liquid pipe 21 and the 2# noble liquid pipe, and let the low-grade noble liquid flow from the 3# noble liquid pipe 23 to the 3# stirring tank 33. This cycle continues, so that the high-grade noble liquid, medium-grade noble liquid, and low-grade noble liquid are collected in the 1# stirring tank 31, the 2# stirring tank 32, and the 3# stirring tank 33 respectively.

[0042] According to the calcium ion concentration in high-grade precious liquid, medium-grade precious liquid and low-grade precious liquid, add appropriate scale inhibitors (polyaspartic acid, sodium citrate carboxyl and methyl chitosan) to the 1# stirring tank 31, 2# stirring tank 32 and 3# stirring tank 33, and stir the reaction thoroughly to make the free calcium ions in each precious liquid form a soluble stable complex, thereby preventing the deposition of substances such as CaCO3.

[0043] After treatment with the composite scale inhibitor, the precious liquid, which has been treated to remove calcium ions, is then transferred through delivery pipes 7 and delivery pumps 8 connected to the outlets of each agitation tank to the first, second, and third adsorption towers 51, 52, and 53, respectively, for activated carbon adsorption. During the delivery process, the flow rate of each precious liquid is monitored by a corresponding flow meter 9 to ensure that the high-grade precious liquid passes through the adsorption tower at a flow rate of 25 m³ / h, the medium-grade precious liquid at a flow rate of 17 m³ / h, and the low-grade precious liquid at a flow rate of 10 m³ / h.

[0044] During the adsorption process, the saturated gold-loaded carbon is unloaded in time, and the remaining gold-loaded carbon is dynamically scheduled across groups according to the principle of "the grade of gold-loaded carbon in each group of adsorption towers is distributed from high to low in the direction of liquid flow" to ensure the precise match between grade and adsorption energy efficiency, improve the overall adsorption rate and shorten the adsorption cycle.

[0045] The present invention has been described in detail above through specific and preferred embodiments, but those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A precious liquid fractionation and diversion dynamic cycle cascade adsorption gold extraction process, characterized in that: The steps include: S1. Precious liquid separation and diversion: During the heap leaching process, the grade of the precious liquid in the heap is tested and the precious liquid is separated into high, medium and low grades according to the grade, and then drained into different stirring tanks respectively; S2. Calcium ion targeted inhibition and synergistic scale inhibition treatment: The calcium ion concentration in high-, medium-, and low-grade precious liquids is tested, and corresponding amounts of a composite scale inhibitor consisting of polyaspartic acid, sodium citrate, and carboxymethyl chitosan are added according to the calcium ion concentration to form soluble stable complexes of the free calcium ions in each precious liquid to prevent scaling. S3. Dynamic cross-group carbon circulation gradient adsorption: The high, medium and low grade precious liquids after the addition of composite scale inhibitors are transferred to the corresponding adsorption tower groups at different adsorption flow rates for activated carbon adsorption, and each adsorption tower group is composed of multiple adsorption towers in series; as the adsorption operation proceeds, the grade of activated carbon in each adsorption tower group presents a gradient distribution from high to low according to the direction of liquid flow. In this process, cross-group scheduling and circulation of gold-loaded carbon is required. Specifically, when the gold-loaded carbon in the high-grade adsorption tower group reaches the saturation threshold, the saturated carbon is unloaded, and then the carbon with relatively high gold-loaded carbon grade in the medium-grade adsorption tower group is transferred to the high-grade adsorption tower group, and then the low-grade carbon is transferred to the high-grade adsorption tower group. The gold-loaded carbon with relatively high grade in the high-grade adsorption tower group is transferred to the medium-grade adsorption tower group, and finally the new carbon or regenerated carbon is added to the low-grade adsorption tower group. The entire scheduling cycle operation always follows the principle of "the grade of gold-loaded carbon in each group of adsorption towers is distributed in a gradient from high to low according to the direction of liquid flow"; this is repeated, the high-grade precious liquid always contacts the high-grade gold-loaded carbon, the gold-loaded carbon is quickly saturated, and the remaining gold ions are forced to migrate to the low-grade gold-loaded carbon, forming a directional concentration difference driving force, achieving the effect of precise matching of grade and adsorption energy efficiency, shortening the adsorption equilibrium time, and improving the overall adsorption rate; finally, the residual lean liquid after activated carbon adsorption can be reused for yard spraying.

2. The process for gold extraction by dynamic cycle and cascade adsorption with separation and diversion of precious liquid according to claim 1 is characterized in that: The grades of high-grade, medium-grade and low-grade precious liquids in step S1 are respectively greater than 1.5 g / m 3 , 0.5~1.5g / m 3 Less than 0.5g / m 3 .

3. The process for gold extraction by dynamic cycle and cascade adsorption with separation and diversion of precious liquid according to claim 1 is characterized in that: The addition amount of the composite scale inhibitor in step S2 is calculated based on the unit consumption of calcium ions. If the calcium ion concentration in the precious solution is less than 300 mg / L, polyaspartic acid, sodium citrate carboxyl and methyl chitosan are added at a unit consumption of 1.5 mg / mg, 0.4 mg / mg and 0.1 mg / mg, respectively. If the calcium ion concentration in the precious solution is greater than 300 mg / L, polyaspartic acid, sodium citrate carboxyl and methyl chitosan are added at a unit consumption of 1.8 mg / mg, 0.5 mg / mg and 0.2 mg / mg, respectively.

4. The process for gold extraction by dynamic cycle cascade adsorption with separation and diversion of precious liquid according to claim 2 is characterized in that: In step S3, the adsorption flow rates of the high-grade, medium-grade, and low-grade precious liquids are 25 m³ / h, 17 m³ / h, and 10 m³ / h, respectively.

5. A precious liquid fractionation and diversion dynamic cycle cascade adsorption gold extraction process system, characterized in that: The invention comprises a plurality of heap leaching sites (1), each of which is connected to a 1# expensive liquid pipe (21), a 2# expensive liquid pipe (22) and a 3# expensive liquid pipe (23), all of which are equipped with valves, and all of which are connected to a 1# agitating tank (31), all of which are connected to a 2# agitating tank (32), and all of which are connected to a 3# agitating tank (33). 3), the 1# stirring tank (31), the 2# stirring tank (32) and the 3# stirring tank (33) are respectively connected to the 1# noble liquid pool (41), the 2# noble liquid pool (42) and the 3# noble liquid pool (43) through gravity pipes, and the 1# noble liquid pool (41), the 2# noble liquid pool (42) and the 3# noble liquid pool (43) are respectively connected to the 1# adsorption tower group (51), the 2# adsorption tower group (52) and the 3# adsorption tower group (53) through delivery pipes and delivery pumps, and flow meters (6) are installed on the delivery pipes.

6. A precious liquid fractionation and diversion dynamic cycle cascade adsorption gold extraction process system according to claim 5, characterized in that: The 1# adsorption tower group (51), the 2# adsorption tower group (52) and / or the 3# adsorption tower group (53) are each composed of five adsorption towers connected in series.

Images