A comprehensive utilization method of laterite nickel ore suspension roasting-smelting

Abstract

A method for comprehensive utilization of laterite nickel ore by suspended roasting and smelting belongs to the field of mining and metallurgical engineering technology. The method includes crushing and grinding, heating and decomposition, thermal storage reduction and smelting processes, specifically: firstly, the laterite nickel ore is crushed and ground in a vertical grinding mill, and the crushed laterite nickel ore powder is preheated by collecting and recovering the gas during the heating and decomposition process, dehydrated and dried, and then heated and decomposed in a suspended state to remove impurities such as crystal water and hydroxyl groups to generate a relatively single oxide, and the mineral itself uses its own heat storage to undergo a reduction reaction in a suspended state to generate nickel iron single substance, which is then sent to a smelting furnace after the ore phase conversion is completed to recover nickel iron. The method has a compact process flow, a high degree of environmental protection, and a high nickel iron recovery, providing a new idea for the treatment of laterite nickel ore.

Description

Technical Field

[0001] The invention belongs to the technical field of mining and metallurgical engineering, and specifically relates to a comprehensive utilization method of laterite nickel ore suspension roasting-smelting. Background Art

[0002] Nickel has excellent corrosion resistance and strong machinability, so it has become a key alloying element in stainless steel. Stainless steel manufacturing consumes nearly two-thirds of the nickel produced worldwide, while the remaining nickel is used to produce high-temperature alloys, non-ferrous alloys, copper alloys, electroplating and batteries. It is an irreplaceable metal for the development of the world's industry today. The total amount of nickel ore with a grade higher than 0.5% that can be mined on land in the world is about 300 million tons, of which it is mainly divided into nickel sulfide and laterite nickel ore, and laterite nickel ore accounts for a high proportion, about 70%. Due to the surge in demand for raw materials in recent years, high-grade nickel sulfide ores have been over-exploited and gradually exhausted. Laterite nickel ore is gradually becoming an important source of nickel extraction. At present, the treatment of laterite nickel ore can be mainly divided into wet treatment process and pyrotreatment process. Since a large amount of acid, alkali, etc. are often added as leaching agents during wet treatment, it will cause serious environmental pollution. With the increasingly stringent environmental protection policies, it has brought serious economic pressure, and there are problems such as long leaching cycle and low efficiency. Therefore, pyrotreatment of laterite nickel ore has gradually received attention.

[0003] General pyrometallurgical treatment processes mainly include rotary kiln-electric furnace method, blast furnace smelting nickel iron method, additive enhanced reduction-magnetic separation method, etc. The rotary kiln-electric furnace method is currently the most widely used. However, due to the uneven heating and insufficient reaction during the rotary kiln roasting process, it leads to high energy consumption, imperfect process, serious environmental pollution and other problems that need to be solved urgently. Therefore, inventing a low-cost, high-efficiency emission-reduction method for treating laterite nickel ore is the focus of current research work.

[0004] Patent 201711237484.1 relates to a coal-based vertical furnace direct reduction process for laterite nickel ore, which is carried out by mixing and briquetting laterite nickel ore powder, coal powder, binder and desulfurizer, mixing with reducing agent and then putting into coal-based vertical furnace, and then discharging out of the furnace after preheating, reduction and cooling, and obtaining nickel iron after magnetic separation. Since this process adopts vertical furnace direct reduction, the reduction degree is relatively high, and it has the advantages of large-scale production and mature technology. However, since nickel ore, coal powder, binder and the like need to be mixed and briquette, it has the disadvantages of poor heat transfer effect, complex process and high cost. At the same time, since it adopts coal-based reduction, the sulfur in the coal will affect the reduction process, reduce the reduction rate, and cause pollution. Patent 202010581483.4 relates to a method for smelting laterite nickel ore using the HIsmelt smelting reduction process. The method first preliminarily dries the laterite nickel ore in a drying kiln, then pre-reduces it in a rotary kiln, and then blows it into the furnace through the ore gun of the HIsmelt melting furnace after mixing it with lime, etc., and finally obtains a crude nickel-iron alloy. However, during the pre-reduction process in the rotary kiln, the ore often faces problems such as uneven heating and insufficient pre-reduction. At the same time, the HIsmelt furnace is complicated to operate and requires the addition of additives such as lime and coal powder. It is seriously polluting and consumes a lot of energy. In actual production, it faces the dual challenges of cost and environment. Therefore, in view of the various problems existing in the current beneficiation and smelting process, it is necessary to develop an environmentally friendly, low-cost, and high-processing capacity comprehensive utilization method of laterite nickel ore. Summary of the invention

[0005] The present invention aims to provide a comprehensive utilization method of laterite nickel ore suspension roasting-smelting, which comprehensively recycles laterite nickel ore through the "crushing and grinding-heating decomposition-heat storage reduction-smelting" suspension roasting-smelting technology. That is, firstly, the laterite nickel ore is crushed and ground in a vertical grinding mill, and the crushed laterite nickel ore powder is preheated by collecting and recovering the gas in the heating and decomposition process, dehydrated and dried, and then heated and decomposed in a suspended state to remove impurities such as crystal water and hydroxyl groups to generate relatively simple oxides, and the mineral itself is used to store heat to generate nickel iron in a suspended state. After the ore phase transformation is completed, it is sent to a smelting furnace to recover nickel iron.

[0006] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting of the present invention comprises the following specific steps:

[0007] S1: Crushing and Grinding:

[0008] The laterite nickel ore is crushed to a mineral particle size of less than -2 mm, and the crushed laterite nickel ore powder is preheated with the circulating gas in the subsequent heating and decomposition process of the laterite nickel ore powder. The preheating temperature is 100-300°C, and the residence time is 10-20s, so that the laterite nickel ore powder is dried and dehydrated to obtain the preheated laterite nickel ore; the main reactions are as follows:

[0009] (Ni,Mg)O·SiO 2 ·H 2 O=(Ni,Mg)O·SiO 2 +H 2 O(g);

[0010] S2: Heating decomposition:

[0011] The preheated laterite nickel ore is fed into a suspension roasting furnace, and air and coal gas are introduced into a combustion station arranged at the bottom of the suspension roasting furnace for combustion to form high-temperature gas, so that the laterite nickel ore powder is in a suspended state; the roasting temperature is controlled to be 1000-1200° C., and the roasting time is 5-20 seconds, so that the laterite nickel ore is freed from impurities such as crystal water and hydroxyl groups to obtain a heated and impurity-removed material;

[0012] Furthermore, in S2, the gas generated during the heating process in the suspension roasting furnace is fed into the crushing device to carry the mineral powder into the preheater for preheating.

[0013] The main reactions that may be involved in the raw materials and dehydrated products in the laterite nickel ore in the suspension roaster are:

[0014] (Mg,Fe,Ni) 3 Si 2 O 5 (OH)→(Mg,Fe,Ni)SiO 3 +(Mg,Fe,Ni) 2 SiO 4 +2H 2 O

[0015] Ni 3 Mg 3 Si 2 O 5 OH(s)→3NiO(s)+3MgO(s)+4SiO 4 +4H 2 O(g)

[0016] (Ni,Mg)O·SiO 2 →NiO+MgO+SiO 2

[0017] S3: Thermal storage reduction:

[0018] The heated and impurity-removed material is fed into a reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the reduction roaster is controlled to be 800-1100°C, and the roasting time is 20-60 minutes to obtain the reduced material. The main chemical reaction equations that may be involved are:

[0019] NiO+CO=Ni+CO 2

[0020] CoO+CO=Co+CO 2

[0021] 3Fe 2 O 3 +CO=2Fe 3 O 4 +CO 2

[0022] Fe 3 O 4 +CO=3FeO+CO 2

[0023] Fe 3 O 4 +4CO=3Fe+4CO 2

[0024] FeO+CO=Fe+CO 2

[0025] Furthermore, in S3, the gas generated during the reduction process of the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0026] S4: Smelting:

[0027] The reduced material is fed into a smelting furnace for smelting at a temperature of 1300-1600°C for 30-50 minutes. The molten iron and slag generated by the smelting are discharged from the molten iron outlet and the slag outlet respectively.

[0028] The smelting furnace is preferably an electric furnace.

[0029] Furthermore, the gas generated during the smelting process in the smelting furnace is fed into the suspension roasting furnace as heating gas.

[0030] In the above-mentioned S1, the feed particle size of the laterite nickel ore is not greater than 30 mm.

[0031] In the S2, the coal gas is selected from coke oven gas, blast furnace gas, natural gas cracking gas, and coal gas.

[0032] In the air and gas introduced into the combustion station in step 2, the volume concentration of the gas is 10% to 30%.

[0033] In the S3, the coal gas is selected from coke oven gas, blast furnace gas, natural gas cracking gas, and coal gas.

[0034] In the heat storage reduction stage of S3, the amount of coal gas introduced is 0.2-0.6 m / s according to the mass ratio of the total volume of reducing gas in the coal gas to the mass ratio of the laterite nickel ore powder in the reduction roaster. 3 / kg, the nickel-iron metallization rate reaches 60-95%.

[0035] In the comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the nickel recovery rate is greater than 95%, and the iron recovery rate is greater than 90%.

[0036] Compared with the existing methods, the characteristics and advantages of the present invention are:

[0037] 1. The present invention creatively proposes the "crushing and grinding - heating decomposition - thermal storage reduction - smelting" suspended roasting reduction - smelting technology, which for the first time incorporates the grinding process into an integrated smelting process, and uses the circulating gas generated by the heating decomposition process to feed the ground ore powder into the heating decomposition process.

[0038] 2. During the suspension roasting and heating process, impurities such as crystal water and hydroxyl groups are removed, so that the target mineral forms a relatively single oxide ore, which improves the activity of the mineral reduction reaction. At the same time, the temperature of the mineral itself is also increased during the heating stage, which is conducive to the subsequent reduction reaction.

[0039] 3. Directly utilize the heat stored in the mineral itself during the heating process, so that the mineral can fully react with the reducing gas in a suspended state during the reduction reaction stage. The reduction rate is high, and there is no need for multi-stage roasting, which effectively reduces energy consumption.

[0040] 4. In the heating decomposition and thermal storage reduction stages, the present invention utilizes H in different coal gases to 2 / CO and N 2 The gas concentration in the roasting atmosphere is regulated by the ratio of mixed gases to achieve the best reduction rate of the mineral. Reducing gas is used in both the heating and reduction roasting stages without using coal. The suspension state can effectively improve the reaction efficiency and reduce the generation of polluting gases such as sulfides.

[0041] 5. The present invention is the first to use the suspended roasting reduction-smelting technology to comprehensively recycle laterite nickel ore. The process is compact, environmentally friendly, and nickel-iron recovery is high, providing a new idea for the treatment of laterite nickel ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention is a process flow chart of the comprehensive utilization method of laterite nickel ore suspension roasting-smelting. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with embodiments.

[0044] Example 1

[0045] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the process flow chart of which is shown in Figure 1 , the specific operation method is as follows:

[0046] The main components of the laterite nickel ore in this embodiment are Ni 0.95%, Fe 51.50%, and the remainder is SiO 2 and MgO, the feed particle size of laterite nickel ore is p80=28mm.

[0047] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0048] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0049] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0050] 4. The reduced material is fed into a smelting furnace (an electric furnace in this embodiment) for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 95%, and the iron recovery rate is 92.6%.

[0051] Example 2

[0052] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0053] The main components of the laterite nickel ore in this embodiment are Ni 1.23%, Fe 42.80%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=25mm.

[0054] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0055] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0056] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled at 950°C, and the roasting time is 45 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster at 0.45m3. 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0057] 4. The reduced material is fed into a smelting furnace (an electric furnace in this embodiment) for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 95.6%, and the iron recovery rate is 92.8%.

[0058] Example 3

[0059] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0060] The main components of the laterite nickel ore in this embodiment are Ni 1.51%, Fe 38.23%, and the balance is SiO 2 and MgO. The feed size of laterite nickel ore is p80=22 mm.

[0061] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0062] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0063] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0064] 4. The reduced material is fed into a smelting furnace (an electric furnace in this embodiment) for heating and smelting at a temperature of 1500°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 96% and the iron recovery rate is 92%.

[0065] Example 4

[0066] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0067] The main components of the laterite nickel ore in this embodiment are Ni 1.88%, Fe 28.11%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=30mm.

[0068] 1. First, the laterite nickel ore is fed into a grinding device and crushed to p80=1.5mm. The crushed ore powder is brought into a preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 300°C and the residence time is 10s to dry and dehydrate the laterite nickel ore.

[0069] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1200°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is introduced into the grinding device to bring the ore powder into the preheater for preheating.

[0070] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat storage of the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 60 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0071] 4. The reduced material is fed into the smelting furnace for heating and smelting at a temperature of 1500°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 96.5% and the iron recovery rate is 93.2%.

[0072] Example 5

[0073] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0074] The main components of the laterite nickel ore in this embodiment are Ni 2.23%, Fe 15.20%, and the balance is SiO 2 and MgO. The feed size of laterite nickel ore is p80=28mm.

[0075] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80=1.5mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0076] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal to remove impurities such as crystal water and hydroxyl groups. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state. The temperature is controlled at 1000°C, the roasting time is 15s, and the volume concentration of coal gas in the suspension roaster is 25%. The gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0077] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat storage of the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 60 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roaster as heating gas.

[0078] 4. The reduced material is fed into the smelting furnace for heating and smelting at a temperature of 1500°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 95.28% and the iron recovery rate is 91.3%.

[0079] Example 6

[0080] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0081] The main components of the laterite nickel ore in this embodiment are Ni 2.62%, Fe 12.21%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=30mm.

[0082] 1. First, the laterite nickel ore is fed into a grinding device and crushed to p80=1.5mm. The crushed ore powder is brought into a preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 300°C and the residence time is 10s to dry and dehydrate the laterite nickel ore.

[0083] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1200°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is introduced into the grinding device to bring the ore powder into the preheater for preheating.

[0084] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1100°C, and the roasting time is 55 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.5m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0085] 4. The reduced material is fed into the smelting furnace for heating and smelting at a temperature of 1550°C for 45 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 97.1% and the iron recovery rate is 93.4%.

[0086] Example 7

[0087] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0088] The main components of the laterite nickel ore in this embodiment are Ni 1.34%, Fe 36.13%, and the balance is SiO 2 and MgO. The feed size of laterite nickel ore is p80=25mm.

[0089] 1. First, the laterite nickel ore is fed into a grinding device and crushed to p80 = 0.8 mm. The crushed ore powder is brought into a preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 180 ° C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0090] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 15s, the volume concentration of gas in the suspension roaster is 20%, and the gas generated during the heating process in the suspension roaster is introduced into the grinding device to bring the ore powder into the preheater for preheating.

[0091] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 900°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.5m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0092] 4. The reduced material is fed into the smelting furnace for heating and smelting at a temperature of 1300°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 95.4% and the iron recovery rate is 94.5%.

[0093] Example 8

[0094] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the specific operation method is as follows:

[0095] The main components of the laterite nickel ore in this embodiment are Ni 1.72%, Fe 28.21%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=25mm.

[0096] 1. First, the laterite nickel ore is fed into a grinding device and crushed to p80 = 0.8 mm. The crushed ore powder is brought into a preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 280 ° C and the residence time is 20 seconds to dry and dehydrate the laterite nickel ore.

[0097] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1200°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is introduced into the grinding device to bring the ore powder into the preheater for preheating.

[0098] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat storage of the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 45 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.5m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0099] 4. The reduced material is fed into the smelting furnace for heating and smelting at a temperature of 1550°C for 45 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 96.9% and the iron recovery rate is 94.2%.

[0100] Comparative Example 1

[0101] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting furnace smelting, the specific operation method is as follows:

[0102] The main components of the laterite nickel ore in this embodiment are Ni 0.95%, Fe 51.50%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=28mm.

[0103] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0104] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of gas in the suspension roaster is 60%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0105] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0106] 4. The reduced material is fed into a smelting furnace for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 93.2% and the iron recovery rate is 90.6%, indicating that in the thermal decomposition step, the volume concentration of the coal gas in the air and coal gas introduced into the combustion station affects the recovery rates of nickel and iron.

[0107] Comparative Example 2

[0108] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting furnace smelting, the specific operation method is as follows:

[0109] The main components of the laterite nickel ore in this embodiment are Ni 0.95%, Fe 51.50%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=28mm.

[0110] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0111] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 5%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0112] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 0.4 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0113] 4. The reduced material is fed into a smelting furnace for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting are discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace is fed into the suspension roasting furnace as heating gas. The nickel recovery rate is 91.1% and the iron recovery rate is 89.8%, indicating that in the thermal decomposition step, the volume concentration of the coal gas in the air and coal gas introduced into the combustion station affects the recovery rates of nickel and iron.

[0114] Comparative Example 3

[0115] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting furnace smelting, the specific operation method is as follows:

[0116] The main components of the laterite nickel ore in this embodiment are Ni 0.95%, Fe 51.50%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=28mm.

[0117] 1. First, the laterite nickel ore is fed into the grinding device and crushed to p80 = 1mm. The crushed ore powder is brought into the preheater by the circulating gas generated during the heating and decomposition process. The preheating temperature is 200°C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0118] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0119] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, the roasting time is 50 minutes, and the amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster of 1.0 m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0120] 4. The reduced material was fed into the smelting furnace for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting were discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace was fed into the suspension roasting furnace as heating gas. The nickel recovery rate was 91.5% and the iron recovery rate was 89.7%, indicating that in the thermal regenerative reduction stage, the amount of coal gas introduced affected the nickel and iron recovery rates according to the mass ratio of the total volume of reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster.

[0121] Comparative Example 4

[0122] A comprehensive utilization method of laterite nickel ore suspension roasting-smelting furnace smelting, the specific operation method is as follows:

[0123] The main components of the laterite nickel ore in this embodiment are Ni 0.95%, Fe 51.50%, and the remainder is SiO 2 and MgO. The feed size of laterite nickel ore is p80=28mm.

[0124] 1. First, the laterite nickel ore is fed into a grinding device and crushed to p80 = 1 mm. The crushed ore powder is brought into a preheater by the circulating gas generated during the roasting process. The preheating temperature is 200 ° C and the residence time is 15s to dry and dehydrate the laterite nickel ore.

[0125] 2. The preheated laterite nickel ore is sent from the bottom to the suspension roaster for heating and impurity removal, and impurities such as crystal water and hydroxyl groups are removed. Air and coal gas are introduced into the suspension roaster with a combustion station at the bottom. The ore powder is in a suspended state, the temperature is controlled at 1100°C, the roasting time is 10s, the volume concentration of coal gas in the suspension roaster is 30%, and the gas generated during the heating process in the suspension roaster is fed into the grinding device to bring the ore powder into the preheater for preheating.

[0126] 3. The heated and impurity-removed materials are fed into the reduction roaster, and a nitrogen and coal gas mixture is introduced into the bottom of the reduction roaster. The heat stored in the mineral itself during the heating stage is utilized to cause a reduction reaction in a suspended state. The temperature in the suspension roaster is controlled to be 1000°C, and the roasting time is 50 minutes. The amount of coal gas introduced is based on the mass ratio of the total volume of the reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster within 0.1m 3 / kg, the gas produced during the reduction process in the reduction roaster is fed into the suspension roasting furnace as heating gas.

[0127] 4. The reduced material was fed into the smelting furnace for heating and smelting at a temperature of 1400°C for 50 minutes. The molten iron and slag generated by smelting were discharged from the molten iron outlet and the slag outlet respectively. The gas generated during the smelting process of the smelting furnace was fed into the suspension roasting furnace as heating gas. The nickel recovery rate was 90.3% and the iron recovery rate was 89.2%, indicating that in the thermal storage reduction stage, the amount of coal gas introduced affected the nickel and iron recovery rates according to the mass ratio of the total volume of reducing gas in the coal gas to the laterite nickel ore powder in the reduction roaster.

Claims

1. A comprehensive utilization method of laterite nickel ore suspension roasting-smelting, characterized in that: It includes crushing and grinding, heating and decomposition, heat storage reduction and smelting processes, specifically: the laterite nickel ore is crushed and preheated, then heated and decomposed in a suspension roaster, and then enters the reduction roaster, using the heat storage of the ore itself during the heating stage, and a reduction reaction occurs in a suspended state, and finally the reduced material is fed into a smelting furnace for smelting to generate molten iron and slag; The specific process of thermal decomposition is as follows: the preheated laterite nickel ore is fed into a suspension roasting furnace, air and coal gas are introduced into a combustion station arranged at the bottom of the suspension roasting furnace for combustion to form high-temperature gas, so that the laterite nickel ore powder is in a suspended state; the roasting temperature is controlled to be 1000-1200° C., and the roasting time is 5-20 seconds, so that the laterite nickel ore is freed from impurities such as crystal water and hydroxyl groups, and the material after heating and impurity removal is obtained; The gas generated during the heating process in the suspension roasting furnace is fed into the crushing device to carry the ore powder into the preheater for preheating; The specific process of the thermal storage reduction is as follows: the material after heating and impurity removal is fed into a reduction roaster, a nitrogen and coal gas mixed gas is introduced into the bottom of the reduction roaster, the heat of the mineral itself is stored in the heating stage, a reduction reaction occurs in a suspended state, the temperature in the reduction roaster is controlled to be 800-1100°C, the roasting time is 20-60min, and the reduced material is obtained; The coal gas is selected from coke oven gas, blast furnace gas, natural gas cracking gas, and coal gas; In the heating decomposition stage, the volume concentration of coal gas in the air and coal gas introduced into the combustion station is 10% to 30%; in the thermal storage reduction stage, the amount of coal gas introduced is 0.2 to 0.6 m / s according to the mass ratio of the total volume of reducing gas in the coal gas to the mass ratio of the laterite nickel ore powder in the reduction roaster. 3 / kg, the nickel-iron metallization rate reaches 60-95%.

2. The comprehensive utilization method of laterite nickel ore suspension roasting-smelting according to claim 1, characterized in that: The specific process of crushing and grinding is: The laterite nickel ore is crushed to a mineral particle size of less than -2 mm, and the crushed laterite nickel ore powder is preheated with circulating gas in the subsequent heating and decomposition process of the laterite nickel ore powder, the preheating temperature is 100-300° C., the residence time is 10-20 seconds, and the laterite nickel ore powder is dried and dehydrated to obtain the preheated laterite nickel ore.

3. The comprehensive utilization method of laterite nickel ore suspension roasting-smelting according to claim 1, characterized in that: The gas generated during the reduction process in the reduction calciner is fed as heating gas to the suspension calciner.

4. The comprehensive utilization method of laterite nickel ore suspension roasting-smelting according to claim 1, characterized in that: The specific process of smelting is: The reduced material is fed into a smelting furnace for smelting at a temperature of 1300-1600°C for 30-50 minutes. The molten iron and slag generated by the smelting are discharged from the molten iron outlet and the slag outlet respectively.

5. The comprehensive utilization method of laterite nickel ore suspension roasting-smelting according to claim 1, characterized in that: The smelting furnace is an electric furnace; And / or, the gas generated during the smelting process in the smelting furnace is fed into the suspension roasting furnace as heating gas.

6. The comprehensive utilization method of laterite nickel ore suspension roasting-smelting according to claim 1, characterized in that: In the comprehensive utilization method of laterite nickel ore suspension roasting-smelting, the nickel recovery rate is greater than 95%, and the iron recovery rate is greater than 90%.

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