WO2020073411A1

WO2020073411A1 - Method for extracting nickel, cobalt, and iron from low-grade laterite nickel ore

Info

Publication number: WO2020073411A1
Application number: PCT/CN2018/114823
Authority: WO
Inventors: 刘玉强; 沙滨; 李维舟; 田忠元; 王少华; 黄海丽; 贺来荣; 马永刚; 杜昊; 马海青; 陈小林; 魏建周; 王多江; 朱慧; 马旻锐; 姚菲; 张飞; 杨松林; 秦为涛; 李博文
Original assignee: 金川集团股份有限公司
Priority date: 2018-10-08
Filing date: 2018-11-09
Publication date: 2020-04-16
Also published as: CN111004915A

Abstract

A method for extracting nickel, cobalt, and iron from a low-grade laterite nickel ore: respectively treating a transitional layer laterite nickel ore and a limonite layer laterite nickel ore, the iron grade of an iron ore concentrate produced reaching 60% to 65%; at the same time, employing a resin adsorption technique and by means of evaporation, concentration, and crystallization, producing nickel sulfate and cobalt sulfate products containing 20% to 30% of nickel and containing 1% to 2.2% of cobalt, applicable as raw materials for producing a battery.

Description

Method for extracting nickel, cobalt and iron from low-grade laterite nickel ore

Technical field

The invention relates to the technical field of hydrometallurgy technology, in particular to a method for extracting nickel, cobalt and iron from low-grade laterite nickel ore.

Background technique

With the continuous reduction of nickel sulfide ore resources, laterite nickel ore will be used as the main raw material for the production of nickel products. Generally speaking, according to the chemical composition and mineral properties of laterite nickel ore, it can be divided into three types: limonite layer, transition layer and humus layer. The laterite nickel ore in the humus layer is high in nickel content and low in iron content. It can be produced by pyrometallurgical reduction technology. At present, the technology is relatively mature and has good economic benefits. The laterite nickel ore in the limonite layer has low nickel content and high iron content. If the fire method is used, the amount of reducing agent is large and the amount of valuable metals obtained is small, which is not economical. Wet processing methods such as pressurized acid leaching or normal pressure acid leaching are usually used. After the impurities are removed, the nickel cobalt hydroxide intermediate product is produced. Although the process has been industrialized, it produces a large amount of waste residue and waste liquid. There are no good treatment measures, and the nickel and cobalt hydroxide products produced have high impurity content and can only be sold as intermediate products. There are many shortcomings. The properties of the nickel layer of the laterite in the transition layer are between the laterite in the humus layer and the laterite in the limonite layer. There are many disadvantages in adopting the fire treatment method or the wet treatment method. The shortcomings of fire process and wet process (high pressure acid leaching (HPAL) process, improved high pressure acid leaching, atmospheric pressure acid leaching process) have been described in the invention patent CN104611558A. The invention patent CN104611558A discloses a method for recovering nickel, cobalt, iron and silicon in laterite nickel ore through a combined leaching process. However, there are the following deficiencies: First, it directly pushes the reaction materials in the double-helical pusher reactor to the water-soluble tank. Since the reaction time in the double-helical pusher reactor is very short, it cannot guarantee the full reaction of the materials. Nickel and cobalt The leaching rate of iron cannot be guaranteed. Second, the limonite pulp and the leaching solution are heated separately and then pumped into the pressurized pipeline reactor by the booster pump. Since the leaching solution is an acidic medium, the booster pump transports the heated leaching solution at 95-100 ° C for a long time. Causes equipment corrosion. Third, after the material passes through the pressurized pipeline reactor, the temperature is lowered and the material is discharged, the heat energy cannot be recycled, the system energy consumption is high, and the economy is not good. Fourth, the pressure leaching slag is washed with soda ash solution. This method can be used in the test stage. However, considering the industrial production of laterite nickel ore, the amount of iron slag produced is 100-110% of the original ore. If soda ash washing method is used, Due to the high cost of soda ash and the large amount of consumption, it will result in poor economic operation of the system.

In view of how to solve the problem of high energy consumption of the pyrotechnic process and the technical difficulties in the combined wet process and the pyrotechnic and wet processes mostly focus on the extraction of nickel, only part of the process can recover cobalt, basically there is no mention of recycling iron, and there is no realization The effective comprehensive utilization of iron in laterite nickel ore resources.

Summary of the invention

In view of the problems existing in the existing process technology, the present invention provides a hydrometallurgical method for extracting nickel, cobalt, and iron from low-grade laterite nickel ore by sulfuric acid leaching with short process, small equipment volume, simple operation, high product quality and good economic benefit .

The present invention adopts the following technical solutions:

A method for extracting nickel, cobalt and iron from low-grade laterite nickel ore, characterized in that the method includes the following steps:

(1) The transition layer laterite nickel ore is added with water to make a first slurry. The first slurry and concentrated sulfuric acid are heated and mixed to obtain a mixed slurry. The mixed slurry is diluted with water and then subjected to solid-liquid separation to obtain leaching. Slag and leachate;

(2) The brown iron layer laterite nickel ore is added with water to make a second slurry, and the leaching liquid and the second slurry in step (1) are mixed, followed by pressurization, primary heat exchange, heating, iron removal, and secondary heat exchange to obtain the first One slurry; after the first slurry is depressurized, solid-liquid separation is performed to obtain iron slag and iron removal liquid, and the iron slag is pressed into balls and then roasted to obtain iron concentrate;

(3) Pre-neutralization, impurity removal, resin adsorption, and sulfuric acid analysis of the resin in step (2) to obtain nickel sulfate solution and cobalt sulfate solution. The nickel sulfate solution and cobalt sulfate solution are evaporated and concentrated. Crystallization yields nickel sulfate products and cobalt sulfate products.

According to the above method, it is characterized in that the mass ratio of the laterite nickel ore in the transition layer in step (1) and the laterite nickel ore in the limonite layer in step (2) is 1: (2-3); the first slurry and the first The mass percentage of the second ore pulp is 30% -50%.

According to the above method, it is characterized in that, in step (1), the first slurry and the concentrated sulfuric acid are heated separately to perform the mixing reaction under the following conditions: the first slurry is heated to 60 ℃ -80 ℃, concentrated sulfuric acid is heated to 100 ℃ -150 ℃ 1. The mixing reaction time is 1h-2h.

According to the above method, it is characterized in that the conditions for the dilution of the mixed slurry in step (1) with water are: the mass ratio of the mixed slurry to water is 1: (1.5-2), and the dilution stirring time is 0.5 h-1h.

According to the above method, it is characterized in that the process of obtaining the first slurry in step (2) is as follows: after pressurizing the mixture of the leaching liquid and the second ore slurry in step (1), a heat exchange is performed through the heat exchanger, and The mixture after the first heat exchange is heated, and the heated mixture is reacted through an iron removal autoclave to obtain a second slurry; the heat exchanger includes a shell and a pipe body, and the heat exchanger shell is The mixture and the second slurry in the heat exchanger tube body exchange heat with the second slurry, and the second slurry undergoes secondary heat exchange through the heat exchanger to obtain the first slurry.

According to the above method, it is characterized in that the mixture and the second slurry adopt countercurrent heat exchange; after the mixture undergoes a heat exchange, the temperature rises from 30 ° C-50 ° C to 180 ° C-210 ° C; the second slurry passes After the heat exchanger performs secondary heat exchange, the temperature decreases from 230 ° C-250 ° C to 60 ° C-80 ° C.

According to the above method, characterized in that the heat source for heating the mixture is high-pressure steam, and the mixture is heated to 230 ° C-250 ° C.

According to the above method, it is characterized in that the conditions for the iron slag in step (2) to be calcined before being calcined are: the calcination temperature is 1000 ° C-1200 ° C, and the calcination time is 10min-30min.

According to the above method, the method is characterized in that the process of removing impurities in the step (3) is divided into one stage of impurity removal and two stages of impurity removal. The slag removal returns to the pre-neutralization stage of step (3).

According to the above method, it is characterized in that in step (3), the resin is used to adsorb the iron removal liquid that has undergone the pre-neutralization and impurity removal process to obtain the resin-adsorbed liquid, and the resin-adsorbed liquid is passed into the air and added with lime milk for processing. Process water can be drained out.

Beneficial effect of the present invention: Compared with the existing process, the present invention uses transition layer laterite nickel ore and brown iron layer laterite nickel ore as raw materials, combined with inorganic resin adsorption nickel and cobalt technology to directly produce nickel cobalt sulfate that can be used as a battery raw material Compared with the existing nickel-cobalt hydroxide intermediate products, the crystalline product has high product quality and good economic benefits; the present invention uses the nickel-containing iron solution leached at normal pressure as a leaching agent to react with the laterite nickel ore of the limonite layer, not only to supplement In addition to the amount of nickel in the iron removal liquid, the iron grade in the iron slag is also improved. The iron grade of the iron slag can reach 53-60%. After calcined ball roasting, it can produce 60-65% iron-containing iron concentrate for blast furnace. The comprehensive recycling of iron slag is realized; the present invention uses a heat exchanger to realize the conversion of reaction heat, the temperature of the material in the heat exchanger shell is increased from 30-50 ° C to 180-210 ° C, and the temperature of the material in the heat exchanger tube is from 230 -250 ℃ reduced to 60-80 ℃, compared with the traditional flash evaporation process, has the characteristics of short process, small equipment size, simple operation and so on.

BRIEF DESCRIPTION

Figure 1 is a schematic diagram of the process of the present invention.

detailed description

A method for extracting nickel, cobalt and iron from low-grade laterite nickel ore according to the present invention includes the following steps: (1) The transition layer laterite nickel ore is added with water to prepare a first slurry, and the mass percentage of the first slurry is 30 % -50%, the first slurry is heated to 60 ℃ -80 ℃, concentrated sulfuric acid is heated to 100 ℃ -150 ℃ and mixed to obtain a mixed slurry, mixing reaction time is 1h-2h, the mixed slurry is diluted with water to dilute, dilute The conditions are: the mass ratio of the mixed slurry to water is 1: (1.5-2), the dilution and stirring time is 0.5h-1h, after dilution, solid-liquid separation is carried out to obtain leaching residue and leaching liquid, and the leaching liquid contains iron 80g / L 120g / L; (2) The brown iron layer laterite nickel ore is added into water to make a second slurry, the mass percentage of the second slurry is 30% -50%, the quality of the transition layer laterite nickel ore and the brown iron layer laterite nickel ore The ratio is 1: (2-3); after mixing the leaching liquid and the second ore pulp in step (1), pressurization, primary heat exchange, heating, iron removal, and secondary heat exchange are performed in sequence to obtain the first slurry. The specific process is: : Pressurize the mixture of the leaching liquid and the second ore pulp in step (1), heat exchange through the heat exchanger for one time The temperature of the heated mixture rises from 30 ° C-50 ° C to 180 ° C-210 ° C. The mixture after primary heat exchange is heated to increase the temperature of the mixture from 180 ° C-210 ° C to 230 ° C-250 ° C and keep it for 1h- 2h, preferably, the heating source is high-pressure steam, and the heated mixture is subjected to iron removal autoclave reaction to obtain a second slurry. The heat exchanger includes a shell and a tube body. The second slurry is in the tube body, and the mixture and the second slurry exchange heat. Preferably, the heat exchange method is countercurrent heat exchange. The second slurry undergoes secondary heat exchange through the heat exchanger to obtain the first slurry. After the second heat exchange through the heat exchanger, the temperature of the second slurry is reduced from 230 ℃ -250 ℃ to 60 ℃ -80 ℃; after the first slurry is discharged through the pressure relief valve group, solid-liquid separation is performed to obtain iron Slag and iron removal liquid, iron slag after ball pressing, and then roasted at 1000 ℃ -1200 ℃ for 10min-30min to obtain iron concentrate. The iron concentrate contains 60% -65% iron, which can be used as iron concentrate for blast furnace ironmaking ; (3) Pre-neutralization, impurity removal, resin adsorption, sulfuric acid analysis of the resin in step (2) in order to obtain nickel sulfate Solution and cobalt sulfate solution, nickel sulfate solution contains nickel 30g / L-35g / L, cobalt sulfate solution contains cobalt 2g / L-3g / L, the nickel sulfate solution and cobalt sulfate solution are evaporated, concentrated and crystallized to obtain nickel sulfate product And cobalt sulfate products, nickel sulfate products contain nickel 20% -23%, cobalt sulfate products contain cobalt 1% -2.2%, of which, the impurity removal process is divided into one stage of impurity removal and two stages of impurity removal, one stage of impurity removal The slag is discharged, and the impurity removal slag obtained by the second stage of impurity removal is returned to the pre-neutralization stage; the resin-adsorbed liquid after the pre-neutralization and impurity removal process is used to obtain the resin adsorption liquid. The resin adsorption liquid contains manganese ions. After the resin is adsorbed, the liquid is ventilated into the air while adding lime milk for treatment to obtain process water that can be drained out.

The present invention will be further explained in conjunction with specific embodiments below. Table 1 shows the composition and mass percentage of the ore used in the examples of the present invention.

Table 1 The composition of ore and its mass percentage

Example 1

Take 500kg Sebuku transition layer laterite nickel ore and add water to make the first ore pulp with a mass percentage of 50%, heat the first ore pulp to 70 ℃, weigh 600kg of concentrated sulfuric acid to 150 ° C, and then mix the first ore pulp and concentrated Sulfuric acid was mixed and then leached at normal pressure for 1 hour. After leaching at normal pressure, 1000 kg of water was added for dilution. The dilution and stirring time was 0.5 h. After liquid-solid separation, 1350 L of normal pressure leaching solution and 128 kg of normal pressure leaching residue were obtained.

Take 1000kg Sebuku brown iron layer laterite nickel ore and add water to make a second ore slurry with a mass percentage of 50%. The mixture obtained by mixing the second ore slurry with 1350L of normal pressure leaching solution is heated from 30 ℃ to 185 after a heat exchange. ℃, and then the mixture was heated to 235 ° C with high-pressure steam at 270 ° C, and the reaction was kept for 1 hour; the heated mixture was reacted through an iron-removing autoclave to obtain a second slurry, which was obtained after a second heat exchange The temperature of the first slurry is reduced from 235 ℃ to 75 ℃; after the first slurry is depressurized through the pressure relief valve group, solid-liquid separation is performed to obtain 1290kg iron slag and 4830L iron removal liquid, and 1000g iron slag is taken for ball pressing Then roast at 1200 ℃ for 30min to obtain iron concentrate.

4830L of iron removal liquid was added to lime milk with a mass percentage concentration of 30%, followed by pre-neutralization, one-stage removal of impurities, and two-stage removal of impurities, to obtain 5100L of removal liquid, and then 5100L of removal liquid passed through copper removal resin 、 Nickel and cobalt extraction resin and impurity removal resin adsorption and sulfuric acid analysis resin to obtain 520L nickel sulfate and cobalt sulfate enrichment solution. The 520L nickel sulfate and cobalt sulfate enrichment solution is evaporated, concentrated and crystallized. 75kg of nickel sulfate and cobalt sulfate products for batteries. Table 2 shows the components and contents of the materials produced in Example 1. Compared with the existing process, the iron concentrate produced in Example 1 has an iron grade of greater than 60% and can be sold as a by-product, while producing high-grade nickel sulfate and cobalt sulfate products, which has better economic benefits.

Table 2 Composition and content of materials produced in Example 1

Example 2

Take 500kg Filipino transition layer laterite nickel ore and add water to make the first ore pulp with 50% mass content, heat the first ore pulp to 80 ℃, weigh 650kg concentrated sulfuric acid to 130 ℃, mix the first ore pulp and concentrated sulfuric acid After normal pressure leaching for 50 minutes, 1000 kg of water was added for dilution after normal pressure leaching. The dilution and stirring time was 40 minutes. After liquid-solid separation, 1420 L of normal pressure leaching solution and 163 kg of normal pressure leaching residue were obtained.

Take 1000kg Philippine brown iron layer laterite nickel ore and add water to make a second ore slurry with a mass percentage of 50%. The mixture obtained by mixing the second ore slurry with 1420L of atmospheric leaching solution increases the temperature from 30 ℃ to 190 ℃ after one heat exchange. Then, the mixture was heated to 240 ° C with high-pressure steam at 270 ° C, and the reaction was kept for 1 hour; the heated mixture was reacted through an iron removal autoclave to obtain a second slurry, and the second slurry was subjected to secondary heat exchange to obtain the first Slurry and the temperature was reduced from 240 ℃ to 80 ℃; after the first slurry was depressurized through the pressure relief valve group, solid-liquid separation was carried out to obtain 1150kg iron slag and 4920L iron removal liquid. Take 1000g iron slag for ball pressing before proceeding Iron concentrate is obtained by roasting at 1200 ℃ for 30min.

4920L of iron removal liquid was added to lime milk with a mass percentage concentration of 30%, followed by pre-neutralization, one-stage removal of impurities, and two-stage removal of impurities, to obtain 5210L of removal liquid, and then 5210L of removal liquid was passed through copper removal resin , Nickel and cobalt extraction resin and impurity removal resin adsorption and sulfuric acid analysis resin to obtain 490L nickel sulfate and cobalt sulfate enrichment liquid, 490L nickel sulfate and cobalt sulfate enrichment liquid by evaporation, concentration, crystallization, the final output can be used as production 72kg of nickel sulfate and cobalt sulfate products for batteries. Table 3 shows the components and contents of the materials produced in Example 2. Compared with the existing process, the iron grade of the iron concentrate produced in Example 2 is greater than 60%, and can be sold as a by-product, while producing high-grade nickel sulfate and cobalt sulfate products, which has better economic benefits.

Table 3 The composition and content of the materials produced in Example 2

Example 3

Take 500kg Indonesian transition layer laterite nickel ore and add water to make the first ore pulp with 50% mass content, heat the first ore pulp to 65 ℃, weigh 625kg concentrated sulfuric acid to 140 ℃, mix the first ore pulp and concentrated sulfuric acid After normal pressure leaching for 30 minutes, 1000 kg of water was added for dilution after normal pressure leaching. The dilution and stirring time was 50 minutes. After liquid-solid separation, 1470 L of normal pressure leaching solution and 140 kg of normal pressure leaching residue were obtained.

1000kg Indonesian lignite layer laterite nickel ore was added to make up a second ore pulp with a mass percentage of 50%. The mixture of the second ore pulp and 1470L of normal pressure leaching solution was raised from 30 ℃ to 200 ℃ after a heat exchange. Then, the mixture is heated to 250 ° C with high-pressure steam at 270 ° C, and the reaction is kept for 1 hour; the heated mixture is reacted through an iron-removing autoclave to obtain a second slurry, and the second slurry is subjected to second heat exchange to obtain the first Slurry and the temperature was reduced from 250 ℃ to 85 ℃; after the first slurry was depressurized through the pressure relief valve group, solid-liquid separation was performed to obtain 1310kg iron slag and 5020L iron removal liquid, and then take 1000g iron slag for ball pressing Iron concentrate is obtained by roasting at 1200 ℃ for 30min.

Add 5020L of iron removal liquid to lime milk with a mass percentage concentration of 30%, and then perform pre-neutralization, one-stage removal of impurities, and two-stage removal of impurities, to obtain 5210L of removal liquid, and then 5300L of removal liquid to pass through the copper removal resin. , Nickel and cobalt extraction resin and impurity removal resin adsorption and sulfuric acid analysis resin to obtain 540L nickel sulfate and cobalt sulfate enrichment liquid, the 540L nickel sulfate and cobalt sulfate enrichment liquid is then evaporated, concentrated and crystallized, the final output can be used as production 78kg of nickel sulfate and cobalt sulfate products for batteries. Table 4 shows the components and contents of the materials produced in Example 3. Compared with the existing process, the iron concentrate produced in Example 1 has an iron grade of greater than 60% and can be sold as a by-product, while producing high-grade nickel sulfate and cobalt sulfate products, which has better economic benefits. Table 4 Example 3 Material composition and content

Claims

A method for extracting nickel, cobalt and iron from low-grade laterite nickel ore, characterized in that the method includes the following steps:

(1) The transition layer laterite nickel ore is added with water to make a first slurry. The first slurry and concentrated sulfuric acid are heated and mixed to obtain a mixed slurry. The mixed slurry is diluted with water and then subjected to solid-liquid separation to obtain leaching. Slag and leachate;

(2) The brown iron layer laterite nickel ore is added with water to make a second slurry, and the leaching liquid and the second slurry in step (1) are mixed, followed by pressurization, primary heat exchange, heating, iron removal, and secondary heat exchange to obtain the first One slurry; after the first slurry is depressurized, solid-liquid separation is performed to obtain iron slag and iron removal liquid, and the iron slag is pressed into balls and then roasted to obtain iron concentrate;

(3) Pre-neutralization, impurity removal, resin adsorption, and sulfuric acid analysis of the resin in step (2) to obtain nickel sulfate solution and cobalt sulfate solution. The nickel sulfate solution and cobalt sulfate solution are evaporated and concentrated. Crystallization yields nickel sulfate products and cobalt sulfate products.
The method according to claim 1, characterized in that the mass ratio of the laterite nickel ore in the transition layer in step (1) and the laterite nickel ore in the limonite layer in step (2) is 1: (2-3); The mass percentages of the first ore pulp and the second ore pulp are both 30% -50%.
The method according to claim 1, characterized in that, in step (1), the conditions for the mixed reaction after the first ore pulp and concentrated sulfuric acid are separately heated are: the first ore pulp is heated to 60 ° C-80 ° C, and the concentrated sulfuric acid is heated to 100 ℃ -150 ℃, mixing reaction time is 1h-2h.
The method according to claim 1, characterized in that, in step (1), the conditions for diluting the mixed slurry with water are: the mass ratio of the mixed slurry to water is 1: (1.5-2), diluted The stirring time is 0.5h-1h.
The method according to claim 1, characterized in that the process of obtaining the first slurry in step (2) is: pressurizing the mixture of the leachate and the second ore slurry in step (1) and passing the heat exchanger once Heat exchange, heating the mixture after one-time heat exchange, and heating the mixture through the iron-removing autoclave to obtain a second slurry; the heat exchanger includes a shell and a tube body, and heat exchange The mixture is in the shell of the heat exchanger, and the second slurry is in the heat exchanger tube. The mixture and the second slurry exchange heat, and the second slurry undergoes the second heat exchange through the heat exchanger to obtain the first Slurry.
The method according to claim 5, characterized in that the mixture and the second slurry adopt countercurrent heat exchange; the temperature of the mixture increases from 30 ° C-50 ° C to 180 ° C-210 ° C after one heat exchange; After the second slurry undergoes secondary heat exchange through the heat exchanger, the temperature decreases from 230 ° C-250 ° C to 60 ° C-80 ° C.
The method according to claim 5, wherein the heat source for heating the mixture is high-pressure steam, and the mixture is heated to 230 ° C-250 ° C.
The method according to claim 1, characterized in that the iron slag in step (2) is subjected to ball pressing and then roasted under the conditions that the roasting temperature is 1000 ° C-1200 ° C and the roasting time is 10min-30min.
The method according to claim 1, characterized in that, in step (3), the impurity removal process of the iron removal liquid is divided into one-stage impurity removal and two-stage impurity removal, and the one-stage impurity removal slag is discharged, and the second stage The impurity removal slag obtained by impurity removal is returned to the pre-neutralization step of step (3).
The method according to claim 1, characterized in that, in step (3), resin is used to adsorb the iron removal liquid which has undergone the pre-neutralization and impurity removal processes to obtain the resin-adsorbed liquid, and the resin-adsorbed liquid is passed into the air while adding lime The milk is processed to obtain process water that can be drained out.