CN116770065A - A method for resource utilization of laterite nickel ore acid leaching residue - Google Patents

Abstract

The invention provides a method for recycling acid leaching residues of laterite-nickel ores, and relates to the technical field of high-value comprehensive utilization of laterite-nickel ores. The method specifically comprises the following steps: s1: acid leaching treatment of laterite nickel ore, S2: pre-neutralizing and precipitating iron, filtering, and S3: removing aluminum and depositing nickel and cobalt, and S4: carbonization desulfurization treatment, S5: quality improvement treatment of iron concentrate powder, S6: and (5) carbonizing and transforming the sulfate solution. Compared with other traditional methods, the method provided by the invention has the advantages that particularly, the iron element components in the prepared iron concentrate are effectively utilized, the sulfur element is effectively reduced, the grade of the iron concentrate is higher, the preparation process flow is short, the cost is low, the efficiency is high, byproducts with lower environmental or economic values are not influenced, and the method is beneficial to industrial mass production and popularization.

Description

A method for resource utilization of laterite nickel ore acid leaching residue

Technical field

The present invention relates to the technical field of high-value comprehensive utilization of laterite nickel ore, and in particular, to a method for resource utilization of acid leaching residue of laterite nickel ore.

Background technique

The traditional pressurized acid leaching process uses sulfuric acid as the leaching agent under high temperature and pressure. By controlling the leaching conditions, most of the iron, aluminum, silicon, etc. are hydrolyzed into the slag, while nickel and cobalt enter the solution to achieve selectivity. After leaching, the leachate is neutralized and impurities (Fe, Al) are removed to obtain high-quality nickel and cobalt solutions.

The biggest advantage of the traditional pressurized acid leaching process is good leaching selectivity and high leaching rate of nickel and cobalt. However, it has complex process technology, high equipment requirements, large investment, high operating cost, serious scarring of the pressurized kettle, and leaching residue. Technical defects such as low iron content and high sulfur content prevent comprehensive utilization.

At present, the main way to deal with laterite nickel ore leaching residue is to directly landfill, which not only causes a serious waste of resources, but also brings a serious burden to the environment, which is not conducive to the construction and sustainable development of a resource-saving and environmentally friendly society. .

For example: Chinese patent CN116004936A discloses a treatment method for laterite nickel ore acid leaching slag, which is to send laterite nickel ore acid leaching slag and solvent to a rotary kiln for oxidation and roasting to desulfurize and remove moisture, and then melt and reduce to obtain a reduced melt. It flows into the electrothermal settling zone to further settle and separate the metallic iron in the slag, then releases the smelting slag through the slag port and quenches it with water to obtain harmless glass slag. The molten iron is released through the metal port into ingots for sale; this method obviously does not affect the laterite nickel ore acid. For efficient utilization of leaching slag, there will still be smelting slag in the end. The reduction process requires the addition of reducing agents and fuels, which consumes more heat energy and is more expensive.

Chinese patent CN110331283A discloses a method for processing acid leaching residue of laterite nickel ore, which involves pre-neutralizing the acid leaching solution after pressurized acid leaching and adjusting the pH value to remove iron and aluminum in one stage to obtain a section of iron and aluminum. slag and a first-stage iron-removing aluminum liquid; use a magnetizing roasting process to process the mixture of a first-stage iron-aluminum slag and an iron-containing acid leaching slag to obtain iron concentrate; then adjust the pH value to perform a second-stage iron and aluminum removal to obtain a second-stage iron and aluminum slag and the second-stage iron-removing aluminum liquid; perform nickel-cobalt precipitation on the second-stage iron-removing aluminum liquid to obtain the lean liquid after nickel-cobalt precipitation and nickel-cobalt precipitate; perform manganese and magnesium precipitation step by step on the lean liquid after nickel-cobalt precipitation, Obtain manganese slag and magnesium slag; return the secondary iron and aluminum slag to the pressurized acid leaching process to improve the metal recovery rate; the process is complicated, the recycled materials have low value, require the use of a large amount of coal resources, and water quenching and roasting consumes a lot of production The cost is relatively high, including but not limited to electricity, heat and water resources, and the grade of iron concentrate obtained can reach up to 65%.

Chinese patent CN104291353A discloses a method for preparing 4A zeolite using laterite nickel ore acid leaching slag as raw material. Obviously, the utilization method is not the precipitation recovery of iron concentrate and alloying elements, but the acid leaching slag is converted into zeolite through alkali melting and hydrothermal reaction. Zeolite has a low added value in the utilization method and does not effectively utilize the iron component in the acid leaching slag.

In view of the shortcomings and deficiencies in the prior art, the present invention provides a method for resource utilization of acid leaching slag of laterite nickel ore. This process realizes desulfurization and resource utilization of iron-containing solid waste slag from pressure leaching of laterite nickel ore, and effectively It solves the problem of open-air dumping of solid waste residue of laterite nickel ore treated by pressurized acid leaching, and at the same time deepens and expands the economic value of the leaching residue. The entire process has no waste water or waste residue emissions, is environmentally friendly, and has huge socio-economic value.

Contents of the invention

The technical problem to be solved by this invention is that the current resource utilization level of laterite nickel ore acid leaching slag is low, especially the iron element component therein has not been effectively utilized, and the main purpose is to convert the acid leaching slag into zeolite or harmless metallurgy. Although the iron element component can be converted into molten iron and iron concentrate through smelting, these existing technologies have more or less problems, such as low utilization rate of iron element in molten iron and large loss. , the grade of iron concentrate can only reach the lower limit of commercial sales, and there are many process steps and difficult operation, which is not conducive to industrial large-scale production and promotion and other technical defects.

In order to solve the above-mentioned objects of the invention, the technical solutions provided by the present invention are as follows:

A method for resource utilization of acid leaching residue of laterite nickel ore. The method for resource utilization of acid leaching residue of laterite nickel ore includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Perform pressure acid leaching treatment on laterite nickel ore to obtain leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use an alkaline substance to adjust the pH of the leaching slurry in S1, add an aluminum removal agent and filter it after sufficient reaction to obtain the main metal leaching solution and iron slag;

S3: Aluminum removal, nickel and cobalt precipitation treatment

Add an aluminum remover to the main metal immersion solution of S2, then use an alkaline substance to adjust the pH to first remove the aluminum, and then use an alkaline substance to adjust the pH to precipitate nickel and cobalt to obtain a nickel and cobalt product;

S4: Carbonization desulfurization treatment

Mix the S2 iron slag with water to make a slurry, and use carbonate to carbonize and desulfurize the slurry, wash and filter it to obtain crude iron concentrate powder and sulfate solution;

S5: Upgrading treatment of iron concentrate powder

Mix S4 crude iron concentrate powder with water, nitric acid or hydrochloric acid to make a slurry, and then perform acidic washing to remove calcium carbonate precipitates in the solution to obtain high-grade iron concentrate powder;

S6: Sulfate solution carbonization transformation treatment

Add calcium oxide to the sulfate solution of S4 to obtain calcium sulfate precipitate and alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain a carbonate solution; wherein: the calcium sulfate precipitate is washed and discharged from the system, and the carbonate solution is recycled Treatment of iron slag extracted from high pressure acid leaching.

Preferably, the pressure leaching conditions in S1 are acid-to-ore ratio 0.2-0.25, liquid-solid ratio 2-3:1, temperature 220-230°C, and leaching time 0.5-1h.

Preferably, the calcium oxide in S2 adjusts the pH of the leaching slurry in S1, and the pH is controlled at 1.8-3.5, and the reaction temperature is 40-80°C; the main components of the iron slag are: TFe is 50-56%, and the S content is 1- 6%.

Preferably, preferably, the aluminum removal agent in S3 is one or more of magnesium oxide or magnesium carbonate; use an alkaline substance to adjust the pH and first control the pH of the aluminum removal at 4.0-5.0, and the aluminum removal temperature at 60-90°C. ; After adjusting the pH with alkaline substances, the pH of the precipitated nickel and cobalt is controlled at 7.0-8.0, and the temperature of the precipitated nickel and cobalt is controlled at 70-80°C.

Preferably, the pulping ratio of iron slag and water in S4 is 1:2.5-8, the alkaline washing temperature of adding carbonate is 50-100°C, and the washing time is 0.5-2h; the main component of iron concentrate: TFe is 54-60% , S content is 0.05-0.3%.

Preferably, the TFe in the main component of the iron slag in S4 is increased by at least 0.6% and the S content is reduced by at least 70% compared to the iron concentrate in S2.

Preferably, the added amount of carbonate in S4 is 0.95-1.1 times the theoretical reaction amount of calcium sulfate and carbonate, and the carbonate is one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate, and potassium carbonate. Sulfate is determined by the type of carbonate added, which is ammonium sulfate, ammonium bisulfate, sodium sulfate, and potassium sulfate. The washing method is reverse secondary washing, that is, new water is used for the second washing, and secondary washing water is used for the first washing. .

Preferably, the acidic washing conditions in S5 are iron concentrate: water = 1:3-5, the reaction temperature is 40-60°C, and the amount of nitric acid or hydrochloric acid added is 0.8-1.2 times the theoretical amount of calcium carbonate in the iron concentrate; The main components of high-grade iron concentrate are: TFe is 62-68% and S content is 0.020-0.040%.

Preferably, the reaction conditions for adding calcium oxide to the sulfate solution in S6 are: reaction temperature 25-50°C, time 1.5-2.0h, and the amount of calcium oxide added is 0.8-1.2 times the theoretical amount of sulfate radicals consumed in the sulfate solution. , the pH is controlled at 8-12; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 0.2-1.0L/h, the temperature is 70-80°C, and the time is 1.0-2.0h.

Preferably, the product after the reaction of carbon dioxide in the alkaline solution in S6 is one of ammonium sulfate, ammonium bisulfate, sodium sulfate, and potassium sulfate.

Compared with the existing technology, the above technical solution has at least the following beneficial effects:

In the above scheme, the present invention proposes a method for resource utilization of laterite nickel ore acid leaching slag, using high-pressure acid leaching to obtain mixed slurry and pre-neutralizing it to obtain the main metal leaching solution and iron slag, where the iron slag is used for iron concentrate. In the preparation of ore, the total iron content of the prepared iron concentrate can reach up to 68%, and the S content can reach as low as 0.020%.

The iron content in the main metal leaching solution of the present invention is not recovered into the prepared iron concentrate. The recovery process does not require coal blending roasting and water quenching, nor does it require weak magnetic separation. The process steps are simple. The process is short, the iron concentrate prepared has higher grade, low cost and high efficiency.

The iron concentrate prepared by the present invention has extremely low sulfur content, good carbon desulfurization efficiency, does not produce sulfur dioxide and other by-products that affect the environment or have low economic value, and does not require multiple large additions of calcium hydroxide. The process Simple, short process and high efficiency.

The carbonization desulfurization and carbonization transformation of the present invention prevents sulfate ions from being doped in the iron concentrate, fully reduces the sulfur content in the iron concentrate, and increases the carbon content in the iron concentrate, and the obtained carbonate Solution circulation is used for the treatment of iron slag leached by high-pressure acid leaching, which is beneficial to industrial production.

In short, compared with other traditional methods, the method of the present invention can effectively utilize the iron component and effectively reduce the sulfur element in the prepared iron concentrate. The grade of the iron concentrate is higher, the preparation process is short, the cost is low, and the efficiency is high. It is high, will not affect the environment or produce low economic value by-products, and is conducive to industrial large-scale production and promotion.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a flow chart of a method for resource utilization of laterite nickel ore acid leaching residue according to the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Example 1

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 500g of limonite-type laterite nickel ore with 120g of concentrated sulfuric acid with a concentration of 98% and 880g of water to make a pulp. Then, at a reaction temperature of 230°C, add a high pressure of 3MPa and react for 0.5 hours to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 20% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 2.5 and the reaction temperature is 70°C to obtain the main metal leaching solution and 415g of iron slag; the main components of the iron slag are: 50% TFe, S content is 4%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 20% magnesium oxide slurry to remove aluminum first, control the pH at 4.5, and control the aluminum removal temperature at 60°C; then use 20% magnesium oxide slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7.5, and the temperature for precipitating nickel and cobalt is controlled at 70°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix the iron slag of S2 with water and make a slurry. Use carbonate to carbonize and desulfurize the slurry, wash it, and filter it. The ratio of iron slag to water is 1:3, and 99.6g of ammonium carbonate is added. The alkaline washing temperature is 70°C and the washing time is 1 hour; 396.3g of crude iron concentrate powder and ammonium sulfate solution are obtained; among them: the main components of the iron concentrate: TFe is 54.2% and the S content is 0.082%;

S5: Upgrading treatment of iron concentrate powder

After adding 396.3g of S4 iron concentrate to 1600g of water for pulping, add 97.97g of 60% concentration nitric acid, the reaction temperature is 50°C, the reaction time is 2h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; The main components of high-grade iron concentrate are: TFe is 63%, S content is 0.040%;

S6: Ammonium sulfate solution carbonization transformation treatment

Add calcium oxide to the ammonium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature for adding 30g of calcium oxide is 40°C, the time is 2.0h, and the pH Control at 9; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 1.0L/h, the temperature is 80°C, and the time is 1.0h; the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution The cycle is used for the treatment of iron slag leached by high-pressure acid leaching.

Example 2

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 500g of limonite-type laterite nickel ore with 150g of concentrated sulfuric acid with a concentration of 98% and 1350g of water to make a pulp. Then, at a reaction temperature of 230°C, add a high pressure of 3MPa and react for 1.0 hours to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 30% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 2.5 and the reaction temperature is 80°C to obtain the main metal leaching solution and 405g of iron slag; the main components of the iron slag are: TFe 52%, S content is 4.94%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 20% magnesium oxide slurry to remove aluminum first, control the pH at 4.5, and control the aluminum removal temperature at 60°C; then use 20% magnesium oxide slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7.5, and the temperature for precipitating nickel and cobalt is controlled at 60°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix the iron slag of S2 with water and make a slurry. Use carbonate to carbonize and desulfurize the slurry, wash it, and filter it. The ratio of iron slag to water is 1:3, and 114.34g of ammonium carbonate is added. The alkaline washing temperature is 70°C and the washing time is 1 hour; 382.46g of crude iron concentrate powder and ammonium sulfate solution are obtained; among them: the main components of the iron concentrate: TFe is 56% and the S content is 0.032%;

S5: Upgrading treatment of iron concentrate powder

After adding 396.3g of S4 iron concentrate to 1600g of water for pulping, add 97.97g of 60% concentration nitric acid, the reaction temperature is 50°C, the reaction time is 2h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; The main components of high-grade iron concentrate are: TFe is 66.28%, S content is 0.025%;

S6: Ammonium sulfate solution carbonization transformation treatment

Add calcium oxide to the ammonium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature for adding 35g of calcium oxide is 40°C, the time is 1.5h, and the pH Control at 10; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 2.0L/h, the temperature is 70°C, and the time is 1.5h; the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution The cycle is used for the treatment of iron slag leached by high-pressure acid leaching.

Example 3

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 500g of limonite-type laterite nickel ore with 100g of concentrated sulfuric acid with a concentration of 98% and 1150g of water to make a pulp. Then, at a reaction temperature of 220°C, add a high pressure of 2.8MPa and react for 1.0 hours to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 10% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 3.0 and the reaction temperature is 80°C to obtain the main metal leaching solution and 410g of iron slag; the main components of the iron slag are: TFe 51.7%, S content is 3.76%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 20% magnesium oxide slurry to remove aluminum first, control the pH at 5.0, and control the aluminum removal temperature at 60°C; then use 20% magnesium oxide slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7.5, and the temperature for precipitating nickel and cobalt is controlled at 60°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix S2 iron slag and water to make slurry, use sodium carbonate to carbonize and desulfurize the slurry, wash, and filter. The ratio of iron slag to water is 1:2.5, and 51.1g sodium carbonate alkali is added. The washing temperature was 70°C and the washing time was 1 hour; 395.3g of crude iron concentrate powder and sodium sulfate solution were obtained; among them: the main components of the iron concentrate: TFe is 56.7% and the S content is 0.060%;

S5: Upgrading treatment of iron concentrate powder

After adding 395.3g of S4 iron concentrate to 1900g of water for pulping, add 106.35g of 60% concentration nitric acid, the reaction temperature is 60°C, the reaction time is 3h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; The main components of high-grade iron concentrate are: TFe is 67%, S content is 0.022%;

S6: Sodium sulfate solution carbonization transformation treatment

Add calcium oxide to the sodium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature of adding 27g of calcium oxide is 30°C, the time is 1.5h, and the pH Control it at 10; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 1.5L/h, the temperature is 80°C, and the time is 1.0h; the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution The cycle is used for the treatment of iron slag leached by high-pressure acid leaching.

Example 4

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 1000g of limonite-type laterite nickel ore with 225g of concentrated sulfuric acid with a concentration of 98% and 1780g of water to make a pulp. Then, at a reaction temperature of 225°C, add a high pressure of 2.9MPa and react for 1 hour to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 30% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 2.5 and the reaction temperature is 60°C to obtain the main metal leaching solution and 800g of iron slag; the main components of the iron slag are: TFe 54%, S content is 3%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 30% magnesium carbonate slurry to remove aluminum first, control the pH at 4.7, and control the aluminum removal temperature at 70°C; then use 30% magnesium oxide slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7, and the temperature of precipitating nickel and cobalt is controlled at 80°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix the iron slag of S2 with water and make a slurry. Use sodium carbonate to carbonize and desulfurize the slurry, wash it, and filter it. The ratio of iron slag to water is 1:6, and 51g of sodium carbonate is added to make it alkaline. The washing temperature is 100°C and the washing time is 2 hours; 773g of crude iron concentrate powder and sodium sulfate solution are obtained; among them: the main components of the iron concentrate: TFe is 56% and the S content is 0.08%;

S5: Upgrading treatment of iron concentrate powder

After adding 773g of S4 iron concentrate to 3865g of water for pulping, add 210g of 60% concentration nitric acid, the reaction temperature is 60°C, the reaction time is 5h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; high-grade The main components of iron concentrate are: TFe is 66%, S content is 0.02%;

S6: Sodium sulfate solution carbonization transformation treatment

Add calcium oxide to the sodium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature of adding 52g of calcium oxide is 50°C, the time is 2h, and the pH is controlled The reaction conditions for introducing carbon dioxide into the alkaline solution in 10; are: the flow rate of carbon dioxide is 1L/h, the temperature is 75°C, and the time is 2h; the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution is recycled for Treatment of iron slag leached by high pressure acid leaching.

Example 5

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 1000g of limonite-type laterite nickel ore with 210g of concentrated sulfuric acid with a concentration of 98% and 1700g of water to make a pulp. Then, at a reaction temperature of 228°C, add a high pressure of 3.0MPa and react for 0.8 hours to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 30% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 2.8 and the reaction temperature is 70°C to obtain the main metal leaching solution and 806g of iron slag; the main components of the iron slag are: TFe 54%, S content is 2%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 30% magnesium oxide slurry to remove aluminum first, control the pH at 4.9, and control the aluminum removal temperature at 73°C; then use 30% magnesium carbonate slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7.2, and the temperature for precipitating nickel and cobalt is controlled at 76°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix the iron slag of S2 with water and make a slurry. Use sodium carbonate to carbonize and desulfurize the slurry, wash it, and filter it. The ratio of iron slag to water is 1:7, and 53g of sodium carbonate is added to make it alkaline. The washing temperature is 87°C and the washing time is 2 hours; 775g of crude iron concentrate powder and sodium sulfate solution are obtained; among them: the main components of the iron concentrate: TFe is 57% and the S content is 0.075%;

S5: Upgrading treatment of iron concentrate powder

After adding 775g of S4 iron concentrate to 3800g of water for pulping, add 220g of 60% concentration nitric acid, the reaction temperature is 58°C, the reaction time is 5h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; high-grade The main components of iron concentrate are: TFe is 65.8%, S content is 0.023%;

S6: Sodium sulfate solution carbonization transformation treatment

Add calcium oxide to the sodium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature for adding 55g of calcium oxide is 48°C, the time is 1.7h, and the pH Control at 11; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 0.8L/h, the temperature is 78°C, and the time is 1.7h; while the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution The cycle is used for the treatment of iron slag leached by high-pressure acid leaching.

Example 6

A method of resource utilization of acid leaching residue of laterite nickel ore. The method of resource utilization of acid leaching residue of laterite nickel ore is shown in Figure 1 and includes the following steps:

S1: Acid leaching treatment of laterite nickel ore

Mix 700g of limonite-type laterite nickel ore with 165g of concentrated sulfuric acid with a concentration of 98% and 1530g of water to make a pulp. Then, at a reaction temperature of 227°C, add a high pressure of 2.9MPa and react for 0.9 hours to obtain a leaching slurry;

S2: Pre-neutralization of heavy iron and filtration

Use 30% calcium oxide slurry to adjust the pH of the leaching slurry in S1. The pH is controlled at 2.5 and the reaction temperature is 68°C. The main metal leaching solution and 563g of iron slag are obtained; the main components of the iron slag are: TFe 53%, S content is 4%;

S3: Aluminum removal, nickel and cobalt precipitation treatment

For the main metal immersion solution of S2, adjust the pH with 30% magnesium oxide slurry to remove aluminum first, control the pH at 4.5, and control the aluminum removal temperature at 70°C; then use 30% magnesium oxide slurry to adjust the pH to precipitate nickel and cobalt. Control it at 7.5, and the temperature for precipitating nickel and cobalt is controlled at 76°C to obtain nickel and cobalt products;

S4: Carbonization desulfurization treatment

Mix the iron slag of S2 with water and make a slurry. Use sodium carbonate to carbonize and desulfurize the slurry, wash it, and filter it. The ratio of iron slag to water is 1:7, and 51g of sodium carbonate is added to make it alkaline. The washing temperature is 98°C and the washing time is 2 hours; 542g of crude iron concentrate powder and sodium sulfate solution are obtained; among them: the main components of the iron concentrate: TFe is 56.5% and the S content is 0.07%;

S5: Upgrading treatment of iron concentrate powder

After adding 542g of S4 iron concentrate to 2512g of water for pulping, add 153g of 60% concentration nitric acid, the reaction temperature is 55°C, the reaction time is 6h, remove the calcium carbonate precipitate in the solution, and obtain high-grade iron concentrate powder; high-grade The main components of iron concentrate are: TFe is 67%, S content is 0.022%;

S6: Sodium sulfate solution carbonization transformation treatment

Add calcium oxide to the sodium sulfate solution of S4 to obtain calcium sulfate precipitation and an alkaline solution, and then pass carbon dioxide into the alkaline solution to obtain an ammonium carbonate solution; where: the reaction temperature of adding 38.5g of calcium oxide is 47°C, the time is 2h, and the pH Control at 9; the reaction conditions for introducing carbon dioxide into the alkaline solution are: the flow rate of carbon dioxide is 0.9L/h, the temperature is 77°C, and the time is 2h; the calcium sulfate precipitate is washed and discharged from the system, and the ammonium carbonate solution is circulated Used for the treatment of iron slag leached by high-pressure acid leaching.

In the above scheme, the present invention proposes a method for resource utilization of laterite nickel ore acid leaching slag, using high-pressure acid leaching to obtain mixed slurry and pre-neutralizing it to obtain the main metal leaching solution and iron slag, where the iron slag is used for iron concentrate. In the preparation of ore, the total iron content of the prepared iron concentrate can reach up to 68%, and the S content can reach as low as 0.020%.

The iron content in the main metal leaching solution of the present invention is not recovered into the prepared iron concentrate. The recovery process does not require coal blending roasting and water quenching, nor does it require weak magnetic separation. The process steps are simple. The process is short, the iron concentrate prepared has higher grade, low cost and high efficiency.

The iron concentrate prepared by the present invention has extremely low sulfur content, good carbon desulfurization efficiency, does not produce sulfur dioxide and other by-products that affect the environment or have low economic value, and does not require multiple large additions of calcium hydroxide. The process Simple, short process and high efficiency.

The carbonization desulfurization and carbonization transformation of the present invention prevents sulfate ions from being doped in the iron concentrate, fully reduces the sulfur content in the iron concentrate, and increases the carbon content in the iron concentrate, and the obtained carbonate Solution circulation is used for the treatment of iron slag leached by high-pressure acid leaching, which is beneficial to industrial production.

In short, compared with other traditional methods, the method of the present invention can effectively utilize the iron component and effectively reduce the sulfur element in the prepared iron concentrate. The grade of the iron concentrate is higher, the preparation process is short, the cost is low, and the efficiency is high. It is high, will not affect the environment or produce low economic value by-products, and is conducive to industrial large-scale production and promotion.

The above is the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (10)

1. The method for recycling the laterite-nickel ore acid leaching slag is characterized by comprising the following steps of:

s1: laterite nickel ore acid leaching treatment

Carrying out pressurized acid leaching treatment on the laterite-nickel ore to obtain leaching slurry;

s2: pre-neutralizing precipitated iron, filtering

Adjusting the pH value of the leached slurry in the step S1 by using alkaline substances, adding an aluminum removing agent for full reaction, and filtering to obtain main metal immersion liquid and iron slag;

s3: aluminum removal and nickel cobalt precipitation treatment

Adding an aluminum removing agent into the main metal immersion liquid of the S2, adjusting the pH value by using an alkaline substance to remove aluminum firstly, and then adjusting the pH value by using the alkaline substance to precipitate nickel and cobalt to obtain a nickel and cobalt product;

s4: carbonization desulfurization treatment

Mixing the iron slag of the S2 with water to prepare slurry, and performing carbonization desulfurization treatment, washing and filtering on the slurry by using carbonate to obtain crude iron concentrate powder and sulfate solution;

s5: upgrading treatment of iron concentrate powder

Mixing the crude iron concentrate powder of the S4 with water, nitric acid or hydrochloric acid to prepare slurry, and then performing acidic washing to remove calcium carbonate precipitate in the solution to obtain high-grade iron concentrate powder;

s6: carbonization conversion treatment of sulfate solution

Adding calcium oxide into the sulfate solution of S4 to obtain calcium sulfate precipitate and alkaline solution, and then introducing carbon dioxide into the alkaline solution to obtain carbonate solution; wherein: and (3) discharging the calcium sulfate precipitate out of the system after washing, and recycling the carbonate solution for treating the iron slag leached by the high-pressure acid leaching.

2. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the pressure leaching condition in S1 is that the acid ore ratio is 0.2-0.25, and the liquid-solid ratio is 2-3: 1. the temperature is 220-230 ℃ and the leaching time is 0.5-1h.

3. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the calcium oxide in S2 adjusts the pH of the leaching slurry in S1, the pH is controlled to be 1.8-3.5, and the reaction temperature is 40-80 ℃; the main components of the iron slag are as follows: TFe 50-56% and S1-6%.

4. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the aluminum removing agent in S3 is one or more of magnesium oxide or magnesium carbonate; adjusting pH with alkaline substance, removing aluminum at pH 4.0-5.0, and removing aluminum at 60-90deg.C; and then regulating pH of the precipitated nickel cobalt to 7.0-8.0 by using alkaline substances, and controlling the temperature of the precipitated nickel cobalt to 70-80 ℃.

5. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the mixing pulping proportion of iron slag and water in S4 is 1:2.5-8, adding carbonate to alkaline washing temperature of 50-100 ℃ and washing time of 0.5-2h; iron ore concentrate main components: TFe is 54-60%, S content is 0.05-0.3%.

6. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the iron concentrate in S4 is improved by at least 0.6% and the S content is reduced by at least 70% compared with the TFe in the main iron slag component in S2.

7. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the adding amount of carbonate in S4 is 0.95-1.1 times of theoretical reaction amount of calcium sulfate and carbonate, the carbonate is one of ammonium carbonate, ammonium bicarbonate, sodium carbonate, sodium bicarbonate and potassium carbonate, and the sulfate is one of ammonium sulfate, ammonium bisulfate, sodium sulfate and potassium sulfate according to the added carbonate type, and the washing mode is reverse secondary washing, namely secondary washing fresh water and primary washing secondary washing water.

8. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the acidic washing condition in S5 is iron ore concentrate: water = 1:3-5, wherein the reaction temperature is 40-60 ℃, and the addition amount of nitric acid or hydrochloric acid is 0.8-1.2 times of the theoretical amount of calcium carbonate in the consumed iron concentrate; the main components of the high-grade iron concentrate are as follows: TFe of 62-68% and S of 0.020-0.040%.

9. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the reaction conditions for adding calcium oxide into the sulfate solution in S6 are as follows: the reaction temperature is 25-50 ℃, the time is 1.5-2.0h, the addition amount of calcium oxide is 0.8-1.2 times of the theoretical amount of sulfate radical in the consumed sulfate solution, and the pH is controlled at 8-12; the reaction conditions for introducing carbon dioxide into the alkaline solution are as follows: the flow rate of the introduced carbon dioxide is 0.2-1.0L/h, the temperature is 70-80 ℃ and the time is 1.0-2.0h.

10. The method for recycling laterite-nickel ore acid leaching slag according to claim 1, wherein the product of the reaction of introducing carbon dioxide into the alkaline solution in the step S6 is one of ammonium sulfate, ammonium bisulfate, sodium sulfate and potassium sulfate.