The laterite nickel ore high pressure leaching slurry concentration control system and method

Abstract

The application provides a laterite nickel ore high pressure leaching slurry concentration control system and method, belongs to the field of metallurgical technology, the system includes: thickener, autoclave, cyclic leaching tank and automatic control device; The underflow of the thickener is connected with the feed end of the autoclave, and the discharge end of the autoclave is connected with the cyclic leaching tank; The automatic control device is used to obtain the iron ion concentration and silicon ion concentration in the cyclic leaching tank, and reduce the slurry concentration of the autoclave when the sum of iron ion concentration and silicon ion concentration exceeds the target concentration threshold. This application reduces the slurry concentration of the autoclave when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, so as to realize the real-time regulation of the iron ion concentration and the silicon ion concentration in the slurry, avoid that more iron ions and silicon ions are leashed in the high pressure leaching stage, and affect the subsequent multi-stage counter current washing flocculation precipitation effect

Description

[0001] Description

[0002] THE LATERITE NICKEL ORE HIGH PRESSURE LEACHING SLURRY CONCENTRATION CONTROL SYSTEM AND METHOD

[0003] FIELD OF THE DISCLOSURE

[0004] The application relates to the field of metallurgical technology, in particular to a laterite nickel ore high pressure leaching slurry concentration control system and method .

[0005] BACKGROUND

[0006] At present , in the process of laterite nickel ore hydrometallurgy, after high pressure leaching, cyclic Leaching and multi-stage pre-neutrali zation of ore slurry, multi-stage counter current washing is needed to fully wash the nickel , cobalt and manganese in the underflow of ore slurry into the solution and carry out solid-liquid separation . However, in practical application, the flocculation precipitation ef fect of multi-stage counter current washing is often poor, which is not conducive to the solid-liquid separation of the solution containing nickel , cobalt and manganese from the slag .

[0007] The poor ef fect of multi-stage counter current washing flocculating precipitation is due to the high concentration of trivalent iron and silicon plasma contained in the slurry, while the high concentration of iron and silicon plasma is due to the high content of iron and silicon in this batch of laterite nickel ore , which leads to the leaching of more iron and silicon plasma in the high-pressure leaching stage . Therefore , it is urgent to provide a regulatory system to prevent the poor flocculation precipitation ef fect of multi-stage counter current washing .

[0008] SUMMARY

[0009] In view of this , it is necessary to provide a high pressure leaching slurry concentration control system and method for laterite nickel ore , to achieve real-time regulation of iron ion concentration and silicon ion concentration in the slurry, so as to avoid more iron ion and silicon ion leaching in the high pressure leaching stage , af fecting the subsequent multi-stage counter current washing flocculation precipitation ef fect .

[0010] In order to solve the above problems , on the one hand, the application provides a laterite nickel ore high pressure leaching slurry concentration control system, including : thickener, autoclave , cyclic leaching tank, ion concentration collection device and automatic control device ;

[0011] The underflow of the thickener is connected with the feed end of the autoclave , and the discharge end of the autoclave is connected with the cyclic leaching tank;

[0012] The ion concentration collection device is used to collect the iron ion concentration and silicon ion concentration in the cyclic leaching tank, and send the iron ion concentration and the silicon ion concentration to the automatic control device ;

[0013] The automatic control device is used to control the reduction of the feed slurry concentration of the autoclave when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold .

[0014] In one possible implementation, the automatic control device is also used to obtain the discharge slurry concentration of the thickener . When the discharge slurry concentration reaches the target concentration value , the feed slurry concentration of the autoclave is controlled to stop decreasing .

[0015] In one possible implementation, obtaining the discharge slurry concentration of the thickener, including

[0016] Obtaining the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow of the thickener, and the sedimentation rate of the flocs ;

[0017] Based on the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow of the thickener, as well as the sedimentation rate of the flocs , the discharge slurry concentration of the thickener is obtained .

[0018] In one possible implementation, the slurry concentration of the thickener is determined based on the following formula :

[0019] Where , vmjnis the sedimentation rate of flocs , Cl is the feed slurry concentration of the thickener, pi is the feed slurry density of the thickener, C2 is the discharge slurry concentration of the thickener, p2 is the discharge slurry density of the thickener, S is the settlement area of the thickener, and G is the discharge volume flow rate of the thickener .

[0020] In one possible implementation, obtaining the sedimentation rate of the flocs , including :

[0021] Obtaining the initial sedimentation rate of the material when no flocculant is added in the thickener ;

[0022] The concentration of the flocculant in the liquid phase of the thickener is obtained . Based on the concentration of the flocculant in the liquid phase , the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate is determined .

[0023] Based on the initial settling rate and the ratio , the settling rate of the flocs is determined .

[0024] In one possible implementation, the ratio between the sedimentation rate of the flocs and the initial sedimentation rate is determined based on the following formula :

[0025] Where , C is the concentration of the flocculant in the liquid phase of the thickener, aPa2and a3is constant calibrated by experiments , and k is the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate .

[0026] In one possible implementation, obtaining the flocculant concentration in the liquid phase of the thickener, including :

[0027] Obtaining the flocculant addition amount , and the feeding slurry concentration and feeding mass flow of the thickener ;

[0028] The flocculant concentration in the liquid phase of the thickener is determined based on the flocculant addition amount , as well as the feed slurry concentration and feed mass flow rate of the thickener .

[0029] In one possible implementation, the flocculant concentration in the liquid phase of the thickener is determined based on the following formula : m = C x (1 — Cx) x v0

[0030] Where , m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of the thickener, Ci is the slurry concentration of the thickener feed, and vo is the mass flow rate of the thickener feed .

[0031] On the other hand, the application also provides a laterite nickel ore high pressure leaching slurry concentration control method, said method is applied in any of the above mentioned system, said method, including :

[0032] The iron ion concentration and silicon ion concentration in the cyclic leaching tank obtained by an automatic control device based on ion concentration collection;

[0033] Based on the automatic control device in the case that the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the feed slurry concentration of the autoclave is controlled to decrease .

[0034] In one possible implementation, the laterite nickel ore high pressure leaching slurry concentration control method also includes :

[0035] The discharging slurry concentration of the thickener is obtained based on the automatic control device , and the feeding slurry concentration of the autoclave is controlled to stop reducing when the discharging slurry concentration reaches the target concentration value .

[0036] The beneficial ef fects of the above implementation are : the laterite nickel ore high pressure leaching slurry concentration control system and method provided in this application, by connecting the underflow of the thickener with the feed end of the autoclave , and connecting the discharge end of the autoclave with the circulation leaching tank; After using the ion concentration detection device to detect the iron ion concentration and silicon ion concentration in the cyclic leaching tank, the iron ion concentration and silicon ion concentration in the cyclic leaching tank are obtained through the automatic control device . When the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the feed slurry concentration of the autoclave is controlled to reduce . In this way, the concentration of iron ions and silicon ions in the slurry can be regulated in real time to avoid the leaching of more iron ions and silicon ions in the high pressure leaching stage , which will af fect the subsequent flocculation precipitation ef fect of multi-stage counter current washing .

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to explain the technical scheme in the embodiments of the application more clearly, the attached drawings needed in the description of the embodiments are briefly introduced in the following . Obviously, the attached drawings described below are only some embodiments of the application, and other attached drawings can be obtained according to the attached drawings without creative labor for the technicians in the field .

[0039] FIG . 1 is the principle block diagram of an embodiment of the control system of high pressure leaching slurry concentration of laterite nickel mine provided in this application;

[0040] FIG . 2 shows the flow chart of one embodiment of the control method for the concentration of high pressure leaching slurry of laterite nickel mine provided in this application .

[0041] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0042] In the following, the technical scheme in the embodiment of the application wil l be clearly and completely described in combination with the attached drawings in the embodiment of the application . Obviously, the embodiment described is only a part of the embodiment of this application, but not the whole embodiment . Based on the embodiments in this application, all other embodiments obtained by persons skilled in this field without making creative labor shall fall within the scope of protection in this application

[0043] In the description of an embodiment of this application, "more than" means two or more unless otherwise stated .

[0044] The terms " including" and "having" in the embodiments of this application, as well as any variation thereof , are intended to cover non-exclusive inclusion, e . g . , a process , method, device , product or device comprising a series of steps or modules need not be limited to those steps or modules clearly listed, Rather, it may include other steps or modules that are not clearly listed or inherent to such processes , methods , products or equipment .

[0045] The naming or numbering of the steps in the embodiment of the application does not mean that the steps in the method process must be executed in the time / logical sequence indicated by the naming or numbering . The execution order of the named or numbered process steps can be changed according to the technical purpose to be reali zed, as long as the same or similar technical ef fect can be achieved .

[0046] The reference to an " embodiment" in this paper means that a particular characteristic, structure or feature described in combination with an embodiment may be included in at least one embodiment of this application . The occurrence of the phrase in various places in the speci fication does not necessarily mean the same embodiment , nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments . What is understood explicitly and implicitly by those skilled in the art is that the embodiment described herein can be combined with other embodiments .

[0047] This application provides a high pressure leaching slurry concentration control system and method for laterite nickel ore , which are explained in the following .

[0048] As shown in Figure 1 , the application provides a laterite nickel ore high pressure leaching slurry concentration control system, including : thickener 101 , autoclave 102 , cyclic leaching tank 103 , ion concentration collection device 105 and automatic control device 104 ;

[0049] The underflow of the thickener 101 is connected with the feed end of the autoclave 102 , and the discharge end of the autoclave 102 is connected with the cyclic leaching tank 103 ;

[0050] The ion concentration collection device 105 is used to collect the iron ion concentration and silicon ion concentration in the cyclic leaching tank 103 , and send the iron ion concentration and the silicon ion concentration to the automatic control device 104 ;

[0051] The automatic control device 104 is used to control the reduction of the feed slurry concentration of the autoclave 102 when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold . It is understandable that the high pressure leaching slurry concentration control system of laterite nickel ore provided by this application includes thickener 101 , autoclave 102 , cyclic leaching tank 103 and automatic control device 104 . The bottom flow of thickener 101 is connected with the feed end of autoclave 102 , and the discharge end of autoclave 102 is connected with the cyclic leaching tank 103 . The automatic control device 104 detects the concentration of iron ions and silicon ions in the cyclic leaching tank 103 in real time through the detection module . When the sum of the concentration of iron ions and silicon ions exceeds the set threshold, the concentration of feed pulp in the autoclave 102 is controlled and reduced, so as to reali ze the real-time regulation of the concentration of iron ions and silicon ions in the pulp . Avoid the leaching of iron ions and silicon ions in the high pressure leaching stage , af fecting the subsequent multi-stage counter current washing flocculation precipitation ef fect .

[0052] The detection port of the ion concentration collection device 105 can be connected with the cyclic leaching tank 103 to obtain part of the pulp in the cyclic leaching tank 103 , and analyze the ion composition of the part of the pulp to obtain the iron ion concentration and silicon ion concentration . It is easy to understand that the ion concentration collection device 105 can use conventional detection equipment and other feasible detection methods in the existing technology to be able to detect the concentration of iron ions and silicon ions in the pulp in the cyclic leaching tank 103 .

[0053] The feed slurry first enters the thickener 101 , where the slurry is thickened based on the principle of gravity sedimentation . The underflow of the thickener is fed into the autoclave 102 to promote the leaching of nickel , cobalt and manganese under the environment of high temperature and high pressure .

[0054] The core idea of this application is : according to the concentration of iron ions and silicon ions in the discharge of autoclave 102 to regulate the slurry concentration of autoclave 102 , in order to improve the flocculation precipitation ef fect of multi-stage counter current washing .

[0055] In some embodiments , the automatic control device 104 is also used to obtain the discharge slurry concentration of the thickener 101 and control the feed slurry concentration of the autoclave 102 to stop decreasing when the discharge slurry concentration reaches a target concentration value .

[0056] It is understandable that the feed slurry concentration of autoclave 102 is consistent with the discharge slurry concentration of thickener 101 . When the discharge slurry concentration of thickener 101 reaches the target concentration value , it means that the feed slurry concentration of autoclave

[0057] 102 also reaches the target concentration value .

[0058] In some embodiments , the discharge slurry concentration of the thickener 101 is obtained, including :

[0059] Obtaining the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow rate of the thickener 101 , and the sedimentation rate of the flocs ;

[0060] Based on the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow of the thickener 101 , as well as the sedimentation rate of the flocs , the discharge slurry concentration of the thickener 101 is obtained .

[0061] Furthermore , the slurry concentration of the thickener 101 is determined based on the following formula :

[0062] Where , vmjnis the sedimentation rate of flocs , Cl is the feed slurry concentration of the thickener, pi is the feed slurry density of the thickener, C2 is the discharge slurry concentration of the thickener, p2 is the discharge slurry density of the thickener, S is the settlement area of the thickener, and G is the discharge volume flow rate of the thickener .

[0063] It is understandable that the core purpose of adding flocculants is to improve the settling rate of materials , and in a given thickener 101 , in order to achieve the target discharge concentration and flow rate of materials , the settling rate of flocculants after adding flocculants needs to meet the above relationship .

[0064] In some embodiments , the sedimentation rate of the flocs is obtained, including : Obtaining the initial sedimentation rate of the material when no flocculant is added in the thickener 101 ;

[0065] The concentration of the flocculant in the liquid phase of the thickener 101 is obtained . Based on the concentration of the flocculant in the liquid phase , the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate is determined .

[0066] Based on the initial settling rate and the ratio , the settling rate of the flocs is determined .

[0067] Furthermore , the ratio between the sedimentation rate of the flocs and the initial sedimentation rate is determined based on the following formula :

[0068] Where , C is the concentration of the flocculant in the liquid phase of the thickener, a , a2and a3is constant calibrated by experiments , and k is the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate .

[0069] It is understandable that the initial settling rate of the material without adding flocculant satis fies the following relationship : . (P3 ~ P o') P (13.95 )2+ 1.09 — — — gd - 13.95 1 Po d

[0070] Where , vais the initial settling velocity, p3 is the density of the material , po is the density of the liquid phase , g is the gravitational acceleration, d is the average particle si ze of the material , and 7] is the initial viscosity of the slurry fed by thickener 101 (without flocculation) .

[0071] With the addition of flocculation agent , the sedimentation rate of the material changes , and there is a proportional relationship between the sedimentation rate of the material and the sedimentation rate without adding flocculation agent , k=Vmin / Va, Vmin is the sedimentation rate of the flocculation after adding flocculation agent , Va is the initial sedimentation rate , and the value of k and the concentration of flocculation agent in the liquid phase meet the above relationship .

[0072] In some embodiments , obtaining the flocculant concentration in the liquid phase of the thickener 101 , including : Obtaining the flocculant addition amount , and the feeding slurry concentration and feeding mass flow of the thickener 101 ;

[0073] The flocculant concentration in the liquid phase of the thickener 101 is determined based on the flocculant addition amount , as well as the feed slurry concentration and feed mass flow rate of the thickener 101 .

[0074] In some embodiments , the flocculant concentration in the liquid phase of the thickener is determined based on the following formula : m = C x (1 — Cx) x v0

[0075] Where , m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of the thickener, Ci is the slurry concentration of the thickener feed, and vo is the mass flow rate of the thickener feed .

[0076] The application also provides a method for controlling the concentration of high pressure leaching pulp of laterite nickel ore . The method is applied in the above system, as shown in Figure 2 . The method comprises :

[0077] 5201 . The iron ion concentration and silicon ion concentration in the cyclic leaching tank 103 obtained by an automatic control device 104 based on ion concentration collection;

[0078] 5202 . Based on the automatic control device 104 in the case that the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the feed slurry concentration of the autoclave 102 is controlled to decrease .

[0079] In some embodiments , the laterite nickel ore high pressure leaching slurry concentration control method also includes :

[0080] The discharging slurry concentration of the thickener 101 is obtained based on the automatic control device 104 , and the feeding slurry concentration of the autoclave 102 is controlled to stop reducing when the discharging slurry concentration reaches the target concentration value .

[0081] It is understood by those skilled in the art that all or part of the procedures for implementing the method of the embodiment may be accomplished by instructing the relevant hardware by a computer program, which may be stored in a computer readable storage medium . Among them, the computer readable storage medium is disk, optical disk, read-only storage memory or random storage memory . The above mentioned control system and method of high pressure leaching pulp concentration of laterite nickel mine provided in this application are introduced in detail . In this paper, a speci fic example is applied to explain the principle and implementation of this application . The explanation of the above embodiment is only used to help understand the method and core idea of this application . At the same time , for the technical personnel in this field, according to the idea of this application, there will be changes in the speci fic implementation and application scope . To sum up, the content of this speci fication should not be understood as a limitation of this application .

Claims

WHAT IS CLAIMED IS1 . A laterite nickel ore high pressure leaching slurry concentration control system, which is characteri zed in that : thickener, autoclave , cyclic leaching tank, ion concentration collection device and automatic control device ;The underflow of the thickener is connected with the feed end of the autoclave , and the discharge end of the autoclave is connected with the cyclic leaching tank;The ion concentration collection device is used to collect the iron ion concentration and silicon ion concentration in the cyclic leaching tank, and send the iron ion concentration and the silicon ion concentration to the automatic control device ;The automatic control device is used to control the reduction of the feed slurry concentration of the autoclave when the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold .2 . According to claim 1 , the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that the automatic control device is also used to obtain the discharge slurry concentration of the thickener . When the discharge slurry concentration reaches the target concentration value , the feed slurry concentration of the autoclave is controlled to stop decreasing .3 . According to claim 2 , the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that obtaining the discharge slurry concentration o f the thickener, includingObtaining the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow of the thickener, and the sedimentation rate of the flocs ;Based on the feed slurry concentration, feed slurry density, discharge slurry density, settlement area and discharge volume flow of the thickener, as well as the sedimentation rate of the flocs , the discharge slurry concentration of the thickener is obtained .4 . According to Claim 3 , the characteristic of the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that the slurry concentration of the thickener is determined based on the following formula :Where , vmjnis the sedimentation rate of flocs , Cl is the feed slurry concentration of the thickener, pi is the feed slurry density of the thickener, C2 is the discharge slurry concentration of the thickener, p2 is the discharge slurry density of the thickener, S is the settlement area of the thickener, and G is the discharge volume flow rate of the thickener .5 . According to claim 3 , the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that obtaining the sedimentation rate of the flocs , including :Obtaining the initial sedimentation rate of the material when no flocculant is added in the thickener ;The concentration of the flocculant in the liquid phase of the thickener is obtained . Based on the concentration of the flocculant in the liquid phase , the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate is determined .Based on the initial settling rate and the ratio , the settling rate of the flocs is determined .6 . According to claim 5 , the characteristic of the laterite nickel ore high pressure leaching slurry concentration control system is that the ratio between the sedimentation rate of the flocs and the initial sedimentation rate is determined based on the following formula :Where , C is the concentration of the flocculant in the liquid phase of the thickener, aPa2and a3is constant calibrated by experiments , and k is the ratio between the sedimentation rate of the flocculant and the initial sedimentation rate .7 . According to claim 5 , the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that obtaining the flocculant concentration in the liquid phase of the thickener, including :Obtaining the flocculant addition amount , and the feeding slurry concentration and feeding mass flow of the thickener ;The flocculant concentration in the liquid phase of the thickener is determined based on the flocculant addition amount , as well as the feed slurry concentration and feed mass flow rate of the thickener .8 . According to claim 7 , the characteristic of the laterite nickel ore high pressure leaching slurry concentration control system is characteri zed in that the flocculant concentration in the liquid phase of the thickener is determined based on the following formula : m = C x (1 — Cx) x v0Where , m is the amount of flocculant added, C is the concentration of flocculant in the liquid phase of the thickener, Ci is the slurry concentration of the thickener feed, and vo is the mass flow rate of the thickener feed .9 . A high pressure leaching slurry concentration control method of laterite nickel ore is characteri zed in that the method is applied to the system mentioned in any of the claims 1- 8 , and the method comprises :The iron ion concentration and silicon ion concentration in the cyclic leaching tank obtained by an automatic control device based on ion concentration collection;Based on the automatic control device in the case that the sum of the iron ion concentration and the silicon ion concentration exceeds the target concentration threshold, the feed slurry concentration of the autoclave is controlled to decrease .10 . According to claim 9 , the laterite nickel ore high pressure leaching slurry concentration control method is characteri zed in that it also includes : the discharging slurry concentration of the thickener is obtained based on the automatic control device , and the feedingslurry concentration of the autoclave is controlled to stop reducing when the discharging slurry concentration reaches the target concentration value .

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