CN111910029A

CN111910029A - Device and method for cooperative quenching and tempering of steel slag and laterite-nickel ore

Info

Publication number: CN111910029A
Application number: CN202010658309.5A
Authority: CN
Inventors: 周和敏; 张俊; 徐洪军; 沈朋飞; 齐渊洪; 林万舟; 郝晓东; 王�锋; 严定鎏; 许海川; 高建军; 何鹏; 王海风
Original assignee: CISRI Sunward Technology Co Ltd
Current assignee: CISRI Sunward Technology Co Ltd
Priority date: 2020-07-09
Filing date: 2020-07-09
Publication date: 2020-11-10

Abstract

The invention discloses a device and a method for synergistic thermal refining treatment of steel slag and laterite-nickel ore, belongs to the technical field of ferrous metallurgy, and solves the problems that in the prior art, rotary kiln reduction and electric furnace melting of laterite-nickel ore have high process energy consumption and low utilization rate of laterite-nickel ore smelting slag, and the existing steel slag treatment method has poor stability and activity of steel slag and is greatly limited in engineering application in the field of building materials. The device for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore comprises a quenching and tempering furnace and a driving mechanism, wherein the quenching and tempering furnace comprises a quenching and tempering furnace molten pool, a steel slag feeding hole and a laterite-nickel ore feeding hole are formed in the upper part of the quenching and tempering furnace, and a coal-oxygen lance is further arranged on the quenching and tempering furnace; the driving mechanism is arranged at the bottom of the hardening and tempering furnace and is used for driving the hardening and tempering furnace to swing and rotate; the steel slag handling device further comprises a molten steel slag handling unit used for transferring the molten steel slag. The device provided by the invention has the advantages of short operation period, low production cost and good steel slag modification effect when used for carrying out cooperative quenching and tempering treatment on the steel slag and the laterite-nickel ore.

Description

Device and method for cooperative quenching and tempering of steel slag and laterite-nickel ore

Technical Field

The invention relates to the technical field of ferrous metallurgy, in particular to a device and a method for the cooperative hardening and tempering of steel slag and laterite-nickel ore.

Background

The nickel-chromium is mainly used as an alloy element, is used for producing stainless steel, high-temperature alloy steel, corrosion-resistant alloy, high-performance special alloy and nickel-based spray coating materials, and has important application in the fields of military industry, aerospace materials and the like. At present, due to the large demand of the fields of stainless steel, nickel alloy, electroplating and the like for nickel, the consumption of nickel ore resources is increasingly large. The globally-mined nickel ore resource comprises 30 percent of nickel sulfide ore and 70 percent of laterite nickel ore. Compared with nickel sulfide ore, the main advantages of developing and utilizing the laterite-nickel ore are as follows: the laterite-nickel ore has rich resources, about 4100 million tons of nickel metal, and low exploration cost; the open-pit mining can be realized, and the mining cost is extremely low; the smelting process is gradually mature; development of stainless steel production increases demand for sintered nickel oxide, nickel iron or general nickel, and these nickel products are mainly derived from laterite-nickel ore; fifthly, laterite-nickel ore resources are mainly distributed in the area near the equator and near the coast, so that the laterite-nickel ore resources are convenient to transport outside. According to the characteristics of smelting process, the treatment process of the laterite-nickel ore can be divided into a pyrogenic process and a wet process, wherein the nickel yield of the pyrogenic process accounts for about 70 percent of the nickel content of the laterite-nickel ore. The pyrometallurgical processes can be classified into sintering-blast furnace reduction melting, rotary kiln pre-reduction-electric furnace melting-refining, sintering-blast furnace vulcanization melting, and the like, according to the difference of the reduction processes. Among them, the rotary kiln prereduction-electric furnace smelting-refining method is the most common method, and is the mainstream process, also called as the RKEF method.

At present, the laterite-nickel ore treated by a sintering-blast furnace reduction smelting method has the defects of high energy consumption, serious pollution and the like; the rotary kiln prereduction-electric furnace smelting-refining method also has the defects of high energy consumption, low treatment efficiency, easy ring formation of the rotary kiln and the like; the sintering-blast furnace sulfidization smelting method has low nickel recovery rate, poor raw material adaptability, needs a large amount of pyrite resources and produces SO₂The smoke pollution problem is serious. With the development of economy, the demand of nickel is continuously increased, the grade of nickel ore is gradually lowered due to the gradual development of nickel resources, and the problems of high energy consumption and the like of the existing laterite-nickel ore treatment method are more prominent. How to develop the reasonable utilization of the low-grade laterite-nickel ore becomes a problem to be solved urgently.

The discharge amount of steel slag in China reaches about 1.4 hundred million tons, and the utilization rate of the steel slag in China is only about 10 percent in recent years. The steel slag is a kind of slag discharged in the steel making process, the discharge amount is large, the discharge amount accounts for 10% -15% of the steel output, and the large discharge of the steel slag not only destroys the ecological environment, but also wastes resources. In fact, the steel slag is a high-quality waste heat resource, the temperature of the liquid steel slag is 1450-1650 ℃, the specific heat capacity is 1.2 kJ/(kg-DEG C), and the enthalpy value can reach 2000MJ/t, which is equivalent to 61kg of standard coal.

The steel slag is a resource capable of being recycled, and the main chemical composition of the steel slag is SiO₂、CaO、Fe₂O₃、Al₂O₃And MgO, etc., but in large-scale application of steel slag, there arePoor volume stability, low gelling activity, large chemical fluctuation and the like, and reduces the utilization rate and the utilization efficiency of the steel slag. The f-CaO and f-MgO contained in the steel slag can generate volume expansion after hydration, which becomes an important factor influencing the stability of the steel slag. After f-CaO in the steel slag is hydrated, Ca (OH) can be generated₂So that the volume of the steel slag is increased by 1.98 times, and the f-MgO in the steel slag is hydrated to generate Mg (OH)₂The volume of the steel slag is increased by 2.48 times. CaO in the steel slag is a main oxide of the steel slag, the content of the CaO is generally 40-60%, and the CaO is mainly used as a calcium source of the steel slag. The higher the CaO content is, the higher the hydraulic activity is, the lower the CaO content is, and the less the amount of the generated gelling activity minerals is, so that the gelling activity of the steel slag is reduced. SiO 2₂The content is generally 8-23%, the calcium silicate mainly reacts with CaO in the steel slag to generate gelled minerals to improve the gelling activity of the steel slag, and the content determines the amount and relative content of the silicate minerals in the steel slag. Al thereof₂O₃The content is generally 3 to 8 percent, which is more beneficial to generating aluminate, iron aluminate or calcium aluminosilicate glass bodies and improving the gelling activity of the high-alumina steel slag.

The concept and principle of steel slag 'component reconstruction' takes the mineral composition of silicate cement clinker as a design target, and adds regulating components into the steel slag to regulate and control the chemical and mineral composition and structure of the steel slag, so as to reconstruct the steel slag and achieve the purposes of stabilizing the quality of the steel slag and regulating and controlling the gelling property of the steel slag.

The conventional steel slag treatment mainly comprises a tray method, a hot stewing method, a water quenching method, a slag box hot splashing method and the like, and the common point of the methods is that a large amount of medium water is used for completing the steel slag treatment process, wherein the hot stewing method and the water quenching method tend to be universal. The steel slag on-line reconstruction is to utilize the high waste heat of the steel slag and add the conditioning components for modification, and the water quenching method is that the high-temperature liquid slag is cooled in the flowing and descending processes, so that the conditioning components cannot be added into the hot steel slag. The viscosity of the steel slag is different according to different steel-making requirements, when the viscosity of the molten slag is higher, smooth water quenching is prevented, and when the pressure and the water quantity of slag flushing water are not controlled properly, explosion can occur, so that potential safety hazards exist. Therefore, the process is not suitable for the steel slag on-line reconstruction technology.

In order to ensure enough waste heat and prevent explosion, the hot stewing method needs to tilt the steel slag into a hot stewing tank when the steel slag is cooled to 300-800 ℃, and the purpose of utilizing the high waste heat of the steel slag at about 1500 ℃ cannot be achieved if thermal conditioning components are added into the slag tank in the process.

The air quenching method in the dry process for treating the thermal-state steel slag is the process with the widest application range, namely, high-temperature molten slag is poured into a slag flowing groove from a slag tank, and is blown into particles by high-speed air at the outlet of the slag flowing groove for later use. The treatment effect of the process is the same as that of the water quenching method, and the conditioning components can not be added into the hot steel slag. And at present, the method is in the position of gradually replacing, so that the air quenching method is not suitable for the on-line reconstruction treatment process of the steel slag.

The laterite-nickel ore has two types, one type is limonite type laterite-nickel ore (high-iron type), and the main components of the laterite-nickel ore are iron-containing oxidized minerals, wherein the total iron content is 40-50%, the nickel content is 0.6-1.2%, and the chromium content is 1.0-1.5%; the other is silicate type (low-iron type), which is usually stored in a deeper layer of an oxidized ore deposit, and comprises 10 to 15 percent of total iron, 1.5 to 1.8 percent of nickel, 1.0 to 5.0 percent of chromium, 38 to 41 percent of silicon oxide and 18 to 20 percent of magnesium oxide; the transition layer contains 25-40% of total iron, 1.0-1.5% of nickel and 1.0-2.5% of chromium.

The brown iron type laterite-nickel ore is extremely high in production cost and is not economical when being used for extracting nickel metal or producing ferronickel; the iron ore is low in grade and can only be added in a small amount as a blending ore at low cost due to the characteristics of nickel and chromium which are associated with the iron ore as common iron ore. Therefore, such ores are generally regarded as rejected ores.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a device and a method for cooperative thermal refining of steel slag and laterite-nickel ore, which can solve at least one of the following problems: (1) the existing method for smelting the laterite-nickel ore has high energy consumption, low nickel recovery rate, poor raw material adaptability and serious pollution; (2) the existing rotary kiln reduction and electric furnace melting separation of the laterite-nickel ore has high process energy consumption and low utilization rate of laterite-nickel ore smelting slag; (3) the laterite nickel ore blast furnace smelting needs to be dried to remove surface water and crystal water and then sintered, and because the strength of the sintered ore is low, the laterite nickel ore blast furnace smelting slag quantity is large, the energy consumption is high, and the laterite nickel ore blast furnace smelting slag is only suitable for small blast furnace smelting; the laterite-nickel ore of the medium-sized blast furnace is only used for ore blending, the ore blending proportion is not high, and otherwise, the production operation of the blast furnace is influenced; (4) the existing steel slag treatment method has poor steel slag stability and activity, and the engineering application in the building material field is greatly limited; (5) the high-temperature sensible heat of the steel slag is not fully utilized in the conventional steel slag treatment method, and the recovery of iron oxide components in the steel slag is low; (6) the existing hot closed operation period of the steel slag reaches 23 hours, and the efficiency is low.

The purpose of the invention is mainly realized by the following technical scheme:

on one hand, the invention provides a device for the cooperative quenching and tempering treatment of steel slag and laterite-nickel ore, which comprises a quenching and tempering furnace and a driving mechanism, wherein the quenching and tempering furnace comprises a quenching and tempering furnace molten pool, the upper part of the quenching and tempering furnace is provided with a steel slag feed port and a laterite-nickel ore feed port, and the quenching and tempering furnace is also provided with a coal-oxygen lance; the driving mechanism is arranged at the bottom of the hardening and tempering furnace and is used for driving the hardening and tempering furnace to rotate and swing; the steel slag handling device further comprises a molten steel slag handling unit used for transferring the molten steel slag.

Further, the device also comprises a riding wheel mechanism, and the riding wheel mechanism is used for supporting the hardening and tempering furnace.

Furthermore, the two sets of riding wheel mechanisms are symmetrically distributed at the bottom of the hardening and tempering furnace.

Furthermore, the coal-oxygen lance comprises a bottom coal-blowing oxygen lance and a side coal-blowing oxygen lance, and a plurality of bottom coal-blowing oxygen lances are arranged at the bottom of the tempering furnace; the plurality of side-blowing coal-oxygen guns are arranged on the side wall of the quenching and tempering furnace.

Furthermore, both ends of the quenching and tempering furnace are respectively provided with a slag outlet and an iron outlet.

Further comprises a pig iron casting and collecting unit, a slag processing unit after tempering and a flue gas processing unit of a tempering furnace.

The invention also provides a method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore, which comprises the following steps:

the method comprises the following steps: pouring the high-temperature molten steel slag into a quenching and tempering furnace;

step two: adding the dried laterite-nickel ore into a quenching and tempering furnace;

step three: and (3) spraying the pulverized coal into a tempering furnace by taking oxygen/oxygen-enriched air as a carrier, and performing tempering treatment to obtain tempered slag and high-temperature molten iron.

Further, in the third step, a part of the pulverized coal is sprayed into the bottom molten iron layer in the quenching and tempering furnace molten pool at a high speed by the bottom coal-blowing oxygen gun, and the other part of the pulverized coal is sprayed into the slag layer in the quenching and tempering furnace molten pool by the side coal-blowing oxygen gun for quenching and tempering.

Furthermore, in the quenching and tempering process, the quenching and tempering furnace is driven by the driving mechanism to swing in a rotating manner.

Further, the method also comprises the following steps:

adjusting the quenching and tempering furnace to a tapping position, and discharging high-temperature molten iron from a tapping hole; and then adjusting the quenching and tempering furnace to a slag outlet position, and discharging quenched and tempered slag from a slag outlet.

Compared with the prior art, the invention has the following beneficial effects:

a) according to the device for the cooperative quenching and tempering of the steel slag and the laterite-nickel ore, the quenching and tempering furnace is arranged, so that the molten steel slag and the quenching and tempering agent can react in the quenching and tempering furnace, the high-temperature phase reaction can be realized by utilizing the sensible heat of the molten steel slag, and the energy consumption is low; and energy is saved. A plurality of sets of bottom coal-blowing oxygen guns and side coal-blowing oxygen guns are arranged along the axial direction (length direction) of the tempering furnace, so that the uniformity of the reaction of a molten pool of the tempering furnace can be ensured and the stirring effect of the molten pool can be improved.

b) The quenching and tempering furnace of the device for the cooperative quenching and tempering of the steel slag and the laterite-nickel ore is supported by 2 sets of riding wheel mechanisms, and the gear rings of 1 set of driving mechanism drive the quenching and tempering furnace to swing and rotate, so that the reduction reaction of metal oxides in a molten pool is accelerated, the operation period of slag quenching and tempering is shortened, and the material distribution in the furnace is more uniform; the tap hole and the slag hole of the quenching and tempering furnace are arranged at two ends of the quenching and tempering furnace, and the quenching and tempering furnace swings and rotates, so that tapping and slag discharging operations are more convenient.

c) The method for the cooperative quenching and tempering of the steel slag and the laterite-nickel ore fully utilizes

Sensible heat of the steel slag melted at the high temperature of 1550-1600 ℃ reduces energy consumption required by reduction of metal oxides in a tempering furnace and tempering and modification of the steel slag; by blowing coal powder and oxygen/oxygen-enriched air into the tempering furnace, iron, nickel and chromium oxides in the steel slag and the laterite-nickel ore are subjected to violent reduction reaction in a molten pool and are converted into nickel-chromium alloy, so that the complete recovery (more than 95%) is realized, the nickel-chromium alloy pig iron can be directly used for steelmaking in a rotary furnace, not only is the iron resource in the steel slag completely recovered, but also a large amount of iron, nickel and chromium resources in the laterite-nickel ore are synchronously recovered. Free CaO, MgO and RO phases in the slag after tempering and reconstruction are carried out on CaO, SiO and MgO rich in the laterite nickel ore and the steel slag, the f-CaO content in the slag after tempering is reduced to below 1 percent and is far lower than the f-CaO content in the untreated steel slag, the volume stability of the steel slag is obviously improved, the steel slag can be used in the field of cement concrete, the activity of the slag after tempering is high (more than S95 grade), and the comprehensive utilization rate of the steel slag reaches 100 percent.

d) According to the method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore, the utilization rate of the residual heat of the molten steel slag is high, the molten steel slag at 1550-1600 ℃ is smelted with the laterite-nickel ore in a quenching and tempering furnace, the steam is recovered from the high-temperature flue gas residual heat after quenching and tempering through a residual heat boiler to generate power, the flue gas at 180-200 ℃ after dust removal is circulated to a dryer, the consumption of drying coal gas is reduced, and the residual heat resource is fully utilized.

e) The method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore has the advantages of short operation period, high production efficiency and low production cost, and the quenching and tempering process is finished within 45 min-1.5 h; the pollutant emission is less.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic view of the overall structure of the device for the cooperative thermal refining of steel slag and laterite-nickel ore of the present invention;

FIG. 2 is a schematic structural diagram of a quenching and tempering unit in the device for the synergistic quenching and tempering of steel slag and laterite-nickel ore;

FIG. 3 is a cross-sectional view at A-A of a thermal refining unit in the device for the cooperative thermal refining of steel slag and laterite-nickel ore of the present invention;

FIG. 4 is a cross-sectional view at B-B of a thermal refining unit in the device for the cooperative thermal refining of steel slag and laterite-nickel ore of the present invention;

FIG. 5 is a cross-sectional view at C-C of a thermal refining unit in the device for the cooperative thermal refining of steel slag and laterite-nickel ore of the present invention;

FIG. 6 is a schematic structural diagram of a slag treatment unit after quenching and tempering in the device for the cooperative quenching and tempering of steel slag and laterite-nickel ore of the invention;

FIG. 7 is a schematic structural diagram of a pig iron casting and collecting unit in a device for synergistic thermal refining of steel slag and laterite-nickel ore according to the present invention;

FIG. 8 is a schematic structural view of a quenching and tempering furnace flue gas treatment unit in the device for the synergistic quenching and tempering of steel slag and laterite-nickel ore of the present invention;

FIG. 9 is a schematic structural view of a molten steel slag hoisting unit in the device for cooperative thermal refining of steel slag and laterite-nickel ore of the present invention;

FIG. 10 is a schematic structural diagram of a drying pretreatment unit in the device for synergistic thermal refining of steel slag and laterite-nickel ore according to the present invention;

FIG. 11 is a flow chart of the method for the cooperative thermal refining of steel slag and laterite-nickel ore of the present invention.

Reference numerals:

a-a thermal refining unit; b-a tempering furnace flue gas treatment unit; c, slag treatment unit after tempering; d-a molten steel slag handling unit; e-a drying pretreatment unit; f-a pig iron casting and collection unit; 1-hoisting a travelling crane by a ladle; 2-a ladle; 3-converter; 4-hoisting the converter slag ladle by using a running vehicle; 5-melting a steel slag ladle; 6-laterite nickel ore storage yard; 7-a grab bucket machine; 8-laterite-nickel ore storage; 9-a crusher; 10-drying the feeding belt; 11-a dryer; 12-gas burner; 13 gas burner combustion fan; 14-drying the flue gas furnace; 15-mixing a circulating flue gas fan; 16-drying the discharging belt; 17-a laterite nickel ore buffer bin; 18-a disk feeder; 19-weighing the belt; 20-drying the flue gas desulfurization tower; 21-drying the flue gas dust remover; 22-drying flue gas induced draft fan; 23-drying the flue gas chimney; 24-feeding and feeding belt; 25-entering a furnace cache bin; 26-a steel slag feed port; 27-a hardening and tempering furnace molten pool; 28-a drive mechanism; 29-riding wheel mechanism; 30-pulverized coal; 31-oxygen/oxygen enriched air; 32-bottom blowing coal oxygen lance; 33-side blowing coal oxygen lance; 34-a taphole; 35-a slag outlet; 36-smoke outlet mask and ascending flue; 37-iron runner; 38-pig machine; 39-a pig iron collection device; 40-slag flushing; 41-slag flushing water; 42-a sedimentation tank; 43-a crane; 44-a slag bath; 45-air nozzles; 46-a post-combustion chamber; 47-gravity dust settling; 48-boiler membrane walls; 49-waste heat boiler; 50-a flue gas temperature regulating air valve; a 51-SDS dry desulfurization milling chamber; 52-flue gas tempering/desulfurization tower; 53-flue; 54-dust collection cloth bag; 55-a dust collection device; 56-induced draft fan; 57-flue gas circulation waste heat utilization pipeline; and 58-chimney.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.

The embodiment provides a device for the cooperative quenching and tempering of steel slag and laterite-nickel ore, which comprises a quenching and tempering unit a as shown in fig. 1 to 10, wherein the quenching and tempering unit a comprises a quenching and tempering furnace, the quenching and tempering furnace comprises a quenching and tempering furnace molten pool 27, and the upper part of the quenching and tempering furnace is provided with a steel slag feeding hole 26 and a laterite-nickel ore feeding hole; the bottom of the tempering furnace is also provided with a driving mechanism 28 and two sets of riding wheel mechanisms 29, the two sets of riding wheel mechanisms 29 are symmetrically distributed at the bottom of the tempering furnace, and the riding wheel mechanisms 29 are used for supporting the tempering furnace; the driving mechanism 28 is used for driving the tempering furnace to perform rotary swing, so that the uniform distribution of materials in the tempering furnace molten pool can be facilitated, and the reaction process in the tempering furnace molten pool can be accelerated; the bottom of the quenching and tempering furnace is also provided with a plurality of bottom coal-blowing oxygen lances 32 along the axial direction (length direction); a plurality of side coal-blowing oxygen lances 33 are arranged on the side wall of the quenching and tempering furnace along the axial direction (length direction); the molten steel slag enters the hardening and tempering furnace molten pool 27 through the steel slag feed inlet 26, the hardening and tempering agent (e.g., laterite-nickel ore) enters the hardening and tempering furnace molten pool 27 through the laterite-nickel ore feed inlet, and the molten steel slag and the hardening and tempering agent can be subjected to hardening and tempering treatment in the hardening and tempering furnace molten pool 27.

Specifically, a furnace entering buffer bin 25 is arranged above the feeding hole of the laterite-nickel ore and used for storing the dried quenching and tempering agent to be fed into the furnace.

Specifically, the two ends of the quenching and tempering furnace are respectively provided with a slag outlet 35 and an iron outlet 34.

For example, as shown in fig. 2 to 5, the quenching and tempering furnace is a cylindrical structure with two closed ends, two sets of riding wheel mechanisms 29 are symmetrically distributed at two axial ends of the quenching and tempering furnace to support the radial lower part of the quenching and tempering furnace, and the quenching and tempering furnace can swing and rotate along the circumferential direction under the support of the riding wheels of the riding wheel mechanisms 29 under the drive of the driving mechanism 28. The radial upper part of the hardening and tempering furnace is provided with a steel slag feeding hole and a hardening and tempering agent feeding hole. The plurality of bottom coal-blowing oxygen lances are axially arranged at the radial bottom of the tempering furnace, and the plurality of side coal-blowing oxygen lances are axially arranged on the circumferential side wall above the radial bottom of the tempering furnace.

Specifically, the device for the cooperative thermal refining of the steel slag and the laterite-nickel ore further comprises a pig iron casting and collecting unit f, as shown in fig. 7, the pig iron casting and collecting unit f comprises an pig iron casting machine 38 and a pig iron collecting device 39; the tap hole 34 is connected with an iron casting machine 38 through an iron runner 37, and high-temperature molten iron flows into the iron casting machine 38 from the tap hole 34 through the iron runner 37 to be cast into nickel-chromium alloy pig iron blocks which are collected by a pig iron collecting device 39 and then sent to a steel plant for steel making.

Or the pig iron casting and collecting unit f includes a hot-metal ladle into which high-temperature molten iron flows from the tap hole 34 to be transported to steel making in a steel plant.

Specifically, the device for the cooperative thermal refining of the steel slag and the laterite-nickel ore further comprises a post-thermal refining slag processing unit c, as shown in fig. 6, the post-thermal refining slag processing unit c comprises a slag runner 40, a sedimentation tank 42, a grab bucket crane 43 and a slag pool 44, a slag hole 35 is connected with the slag runner 40, the thermal refining slag flows into the slag runner 40 through the slag hole 35, is quenched into slag particles of 1-3 mm under the rapid cooling of slag flushing water 41, the slag particles are precipitated through the sedimentation tank 42, are sent into the slag pool 44 for caching through the grab bucket crane 43, and are sent to a subsequent slag grinding process for use in the cement industry.

In order to fully utilize the waste heat of the tempered high-temperature flue gas, the device for the cooperative tempering of the steel slag and the laterite-nickel ore further comprises a tempering furnace flue gas treatment unit b, and as shown in fig. 8, the tempering furnace flue gas treatment unit b comprises a flue gas outlet cover, an ascending flue 36, a post-combustion chamber 46, a gravity dust fall 47, a waste heat boiler 49, a flue gas temperature adjusting/desulfurizing tower 52, a dust collecting cloth bag 54, an induced draft fan 56, a flue gas circulating waste heat utilization pipeline 57 and a chimney 58 which are sequentially connected. High-temperature flue gas (1400-1500 ℃) in the tempering furnace enters the post-combustion chamber 46 through the flue gas outlet cover and the uptake flue 36, and the high-temperature flue gas is rich in CO reducing gas and needs to be completely burnt in the post-combustion chamber 46 (the combustion of CO is completed by injecting air through the air nozzle 45); the flue gas from the post combustion chamber 46 passes through gravity dust fall 47, enters a boiler membrane wall 48 for heat exchange, and then is subjected to slag condensation through a slag condensation pipe in a waste heat boiler 49, heat exchange through a heat exchange pipe bundle and an economizer to generate steam for power generation and energy recovery. The flue gas with the temperature of 180-200 ℃ coming out of the waste heat boiler 49 is mixed with air through a flue gas temperature adjusting air valve 50 to adjust the temperature, so that the subsequent cloth bags are prevented from being burnt out accidentally, the flue gas with the temperature adjusted and the desulfurizer sprayed in a powder preparation room 51 through an SDS dry desulfurization are desulfurized in a flue gas temperature adjusting/desulfurizing tower 52, the desulfurized flue gas enters a dust collecting cloth bag 54 through a flue 53, and dust in the flue gas is collected through the dust collecting cloth bag 54 and is collected by a dust collecting device 55. The 180-200 ℃ flue gas after dust removal through the cloth bag is led out by the draught fan 56 and is sent to the drying intervention treatment unit for recycling by the flue gas circulating waste heat utilization pipeline 57 so as to recycle low-temperature waste heat and save drying energy consumption, and the purified residual flue gas is discharged into the atmosphere through the chimney 58 to achieve standard emission.

Specifically, the device for the cooperative thermal refining of the steel slag and the laterite-nickel ore further comprises a molten steel slag hoisting unit d, as shown in fig. 9, the molten steel slag hoisting unit d comprises a ladle hoisting travelling crane 1, a ladle 2, a converter 3, a converter slag ladle hoisting travelling crane 4 and a molten steel slag ladle 5; the ladle 2 is transported to the converter 3 by the ladle lifting travelling crane 1, the molten iron and the scrap steel are smelted together in the converter 3, the molten steel slag ladle 5 is used for containing high-temperature molten steel slag at 1550-1600 ℃ generated by steel making, and the molten steel slag ladle 5 is transported to the tempering furnace for later use by the converter slag ladle lifting travelling crane 4.

In order to prevent moisture in a conditioner (such as a laterite-nickel ore) from being brought into a high-temperature conditioner furnace and avoid safety accidents, the conditioner (such as a laterite-nickel ore) needs to be dried and pretreated, and the device for the synergistic conditioning of steel slag and the laterite-nickel ore further comprises a drying and pretreatment unit e, as shown in fig. 10, the drying and pretreatment unit e comprises a laterite-nickel ore storage yard 6, a grab bucket machine 7, a laterite-nickel ore bin 8, a crusher 9, a drying and feeding belt 10 and a dryer 11; during implementation, the grab machine 7 grabs the laterite nickel ore into the laterite nickel ore bin 8 from the laterite nickel ore storage yard 6, the laterite nickel ore is input into the crusher 9 through the feeding belt, and the crushed laterite nickel ore is input into the dryer 11 for drying through the drying and feeding belt 10.

Specifically, the drying energy of the dryer 11 is provided by a drying flue gas furnace 14, the drying flue gas furnace 14 comprises a gas burner 12 and a gas burner combustion fan 13, the gas is combusted by combustion air provided by the gas burner 12 and the gas burner combustion fan 13 to obtain combustion hot flue gas (the temperature of the combustion hot flue gas is greater than 1000 ℃), the combustion hot flue gas in the flue gas furnace 14 is input into the dryer 11, the hot flue gas and the water-containing conditioning agent perform gas-solid two-phase heat exchange, and the conditioning agent is dried to 110-120 ℃. The dried quenching and tempering agent is input into a laterite-nickel ore buffer bin 17 through a drying and discharging belt 16, the laterite-nickel ore in the laterite-nickel ore buffer bin 17 is input into a furnace feeding belt 24 through a disk feeder 18 and a weighing belt 19, and is sent into a furnace buffer bin 25 to be used as the quenching and tempering agent for later use.

Specifically, the drying pretreatment unit further comprises a drying flue gas desulfurization tower 20, a drying flue gas dust remover 21, a drying flue gas induced draft fan 22 and a drying flue gas chimney 23; the waste drying flue gas from the dryer 11 is desulfurized in a drying flue gas desulfurization tower 20, then is dedusted by a drying flue gas deduster 21, and is introduced into a drying flue gas chimney 23 by a drying flue gas induced draft fan 22 to achieve standard emission.

Compared with the prior art, the device for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore can realize the reaction of the molten steel slag and the quenching and tempering agent in the quenching and tempering furnace by arranging the quenching and tempering furnace, can realize the high-temperature phase reaction by utilizing the sensible heat of the molten steel slag, and has the advantages of low energy consumption and energy conservation. A plurality of sets of bottom-blowing coal-oxygen guns and side-blowing coal-oxygen guns are arranged along the axial direction (length direction) of the tempering furnace simultaneously, so that the uniformity of the reaction of a melting pool of the tempering furnace is ensured and the stirring effect of the melting pool is improved.

The quenching and tempering furnace of the device for the cooperative quenching and tempering of the steel slag and the laterite-nickel ore is supported by 2 sets of riding wheel mechanisms, and the gear rings of 1 set of driving mechanism drive the quenching and tempering furnace to swing and rotate, so that the reduction reaction of metal oxides in a molten pool is accelerated, the operation period of slag quenching and tempering is shortened, and the material distribution in the furnace is more uniform; the tap hole and the slag hole of the quenching and tempering furnace are arranged at two ends of the quenching and tempering furnace, and the quenching and tempering furnace swings and rotates, so that tapping and slag discharging operations are more convenient.

The invention also provides a method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore, which adopts the device and comprises the following steps:

the method comprises the following steps: pouring 1550-1600 ℃ high-temperature molten steel slag into a quenching and tempering furnace molten pool 27 from a steel slag feeding hole 26, and inputting a dried laterite nickel ore quenching and tempering agent into the quenching and tempering furnace molten pool 27 from the laterite nickel ore feeding hole; the coal powder 30 is carried by oxygen/oxygen-enriched air 31, one part of the coal powder is sprayed into a bottom iron water layer in a molten pool of the tempering furnace at a high speed by a bottom coal-blowing oxygen lance 32, and the other part of the coal powder is sprayed into a slag layer in the molten pool of the tempering furnace by a side coal-blowing oxygen lance 33, so that reduction reaction of iron oxide and tempering of steel slag are carried out, and pig iron containing nickel and chromium and slag after tempering are generated;

step two: when the quenching and tempering furnace is adjusted to the tapping position, high-temperature molten iron flows out from the tapping hole 34; when the quenching and tempering furnace is adjusted to the slag discharging position, the quenched and tempered slag flows out from the slag discharging hole 35.

Specifically, in the second step, when the quenching and tempering furnace is adjusted to the tapping position, high-temperature molten iron at 1500-1550 ℃ flows into an iron casting machine 38 from an iron tapping hole 34 through an iron runner 37, is cast into nickel-chromium alloy pig iron blocks, and is sent to a steel plant for steel making after being collected by a pig iron collecting device 39; or the high-temperature nickel-chromium molten iron flows into the hot-metal ladle from the tap hole 34 and is transported to a steel plant for steel making, so as to smelt stainless steel or corrosion-resistant steel; when the quenching and tempering furnace is adjusted to a slag discharging position, slag subjected to high-temperature quenching and tempering at 1500-1550 ℃ flows into a slag flushing channel 40 from a slag discharging hole 35, is rapidly cooled by slag flushing water 41 to be quenched into slag particles with the diameter of 1-3 mm, the water-quenched slag particles are precipitated by a sedimentation tank 42, are sent into a slag tank 44 by a crane 43 for caching, and are sent to a subsequent slag grinding process for use in the cement industry; or in order to recover the sensible heat of the slag after high-temperature tempering, the slag after tempering is treated by adopting a dry granulation method.

Specifically, in the step one, the high-temperature molten steel slag may be converter steel slag or electric furnace steel slag, and the molten steel slag comprises the following components in percentage by mass: fe₂O₃7％～9％，Fe₃O₄7% -15%, FeO 7% -15%, CaO 40% -60% (exemplary, 35% -45%), SiO₂10％～20％，Al₂O₃0.1％～3％，MgO2％～10％，K₂O0.1％～2％，Na₂0.1 to 2 percent of O and the balance of inevitable impurities, wherein the content of TFe15 to 30 percent.

Specifically, in the first step, the laterite-nickel ore comprises the following components in percentage by mass: fe₂O₃15％～60％，Fe₃O₄7％～15％，FeO2％～6％，CaO0.2％～10％，SiO ₂5％～41％，Al₂O₃2％～5％，MgO11％～20％，Cr1％～2％(Cr₂O₃2.92-5.85 percent of Ni, 0.5-2 percent of Ni (0.64-2.54 percent of Ni), and the balance of inevitable impurities, wherein the total iron TFe 10-50 percent and the metallic iron MFe 0-2 percent.

Specifically, in the first step, oxides of iron, nickel and chromium in the molten steel slag and the laterite-nickel ore are reduced into metal through reduction reaction in a molten pool at 1550-1600 ℃, and oxidation reaction is carried out on pulverized coal. The specific reaction principle in the molten pool is as follows:

(1)oxidation reaction of coal powder: 2C + O₂→2CO(g)

(2) Reduction reaction of metal oxide:

3Fe₂O₃+CO(g)→2Fe₃O₄+CO₂(g)

Fe₃O₄+CO(g)→3FeO+CO₂(g)

FeO+CO(g)→Fe+CO₂(g)

NiO+CO(g)→Ni+CO₂(g)

Cr₂O₃+3CO(g)→3Cr+2CO₂(g)

(3) adding a modifying agent (rich in SiO)₂) Slag reaction:

2CaO+SiO₂→2CaO·SiO₂

2MgO+SiO₂→2MgO·SiO₂

it should be noted that the quenching, tempering, reconstructing and modifying principle of the molten liquid steel slag is as follows:

in the steel slag, the content of CaO is 40-60%, the content of MgO is 5-10%, and the alkalinity is CaO/SiO₂Generally, the alkalinity is higher than 1.8, the higher the alkalinity is, the higher the free calcium oxide f-CaO is, the alkalinity is 3.1-3.5, and 7-13% of the free calcium oxide f-CaO is usually contained. The steel slag mainly contains free calcium oxide f-CaO and a small amount of free magnesium oxide f-MgO. By adding laterite nickel ore (containing SiO)₂And Al₂O₃) Reconstruction modification, reaction in a molten pool to form calcium aluminosilicate and magnesium aluminosilicate, greatly reducing free calcium oxide and free magnesium oxide in the quenched slag, lowering the melting point and viscosity of the slag, leading the alkalinity to be close to about 1.2 of blast furnace slag, leading the obtained vitreous phase to be more than or equal to 95 percent after water quenching, completely achieving the activity of blast furnace granulated slag, reducing the f-CaO content in the quenched slag to be less than 1 percent and far lower than the f-CaO content in the unprocessed steel slag, and greatly improving the volume stability of the reconstructed steel slag.

FeO and Fe with the total iron content of about 20-25 percent in the steel slag are reduced by coal injection in a molten pool₂O₃Reducing into metallic iron to realize slag-iron separation in a tempering furnace, and separating metallic iron, RO phase (divalent metal oxide continuous solid solution with MgO and FeO as main components), calcium ferrite and other high-hardness minerals in the steel slagGreatly reduces the abrasion resistance of the steel slag, obviously improves the key link of the utilization problem of the steel slag. The FeO content in the original steel slag RO phase accounts for 50-60% of the total FeO content in the steel slag, the MgO content in the steel slag RO phase is about 14-20%, and other FeO exists in the silicate, ferrite and iron aluminate phases in a solid solution mode. The majority of the FeO in the steel slag is present in the RO phase. In the reduction and reconstruction process, the injected coal powder has the reduction effect on the iron oxide, and Fe occurs in the occurrence state of Fe element in the reconstruction process³⁺→Fe²⁺Change of → Fe, most of the iron oxides will be reduced to metallic Fe under sufficient reducing agent. Fe during reductive reconstitution²⁺The content of (A) is drastically reduced, FeO in the RO phase is reduced to metallic iron, and the RO phase is decomposed and eliminated. After the addition of the modifying agent, such as laterite-nickel ore, the nickel ore contains rich SiO₂CaO, MgO and Al₂O₃The reduction rate of iron compounds in the steel slag in the tempering furnace is close to 100 percent, the molten steel slag is reduced, more than 90 percent of iron in the steel slag can be recovered, simultaneously, high-activity tailings are generated, the content of glass bodies of the tailings after water quenching is more than or equal to 95 percent, the activity is greatly improved, the content of iron oxide in the tailings is less than 3 percent, and the activity exceeds that of standard cement.

Adding a quenching and tempering agent into liquid steel slag with high temperature of 1550-1600 ℃, spraying coal by a quenching and tempering furnace through total oxygen/oxygen-enriched air, wherein the temperature in the furnace is 1550-1600 ℃, and the temperature required by the reaction of silicate minerals (about 1350 ℃) is satisfied. In addition, due to the strong stirring action of the coal powder and the oxygen-enriched/full-oxygen gas which are injected by the coal-oxygen lance at high speed in the quenching and tempering furnace, the quenching and tempering material and the liquid steel slag are completely and uniformly mixed. The hardening and tempering agent is uniformly mixed with the high-temperature liquid steel slag, and the purpose of modifying the steel slag can be fulfilled on the premise of enough slag temperature and reaction time.

In order to ensure enough waste heat and prevent explosion in the conventional thermal stewing method, the steel slag needs to be tipped into a thermal stewing tank when the steel slag is cooled to 300-800 ℃, a proper amount of water is sprayed to generate saturated steam which reacts with free calcium and magnesium in the slag to generate expansion stress to crush and pulverize the steel slag, and f-CaO and f-MgO in the steel slag are fully digested (the thermal stewing operation period is as long as 23 hours) to form Ca (OH)₂And Mg (OH)₂At the mostThe final f-CaO content is less than 1.5%, and the stability of the cement is improved. Different from the existing hot-stuffy method, the quenching and tempering process of the invention can mix the quenching and tempering modified material with the high-temperature molten liquid steel slag uniformly under the strong stirring of the jet air flow of the coal-oxygen lance and the swinging of the furnace body, and carry out reduction reaction with the coal-oxygen lance sprayed with the pulverized coal, and can finish the modification purpose of the steel slag on the premise of enough slag temperature (1550-1600 ℃) and reaction time (45 min-1.5 h).

In the first step, the coal powder 30 is injected into the molten pool at a high speed by the coal oxygen lance by taking oxygen/oxygen-enriched air 31 as a carrier, the coal powder is used as a reducing agent to react with iron oxide in molten steel slag or iron oxide and nickel-chromium oxide in laterite-nickel ore on one hand, and on the other hand, the reduction reaction of the molten pool is rapid and violent under the high-speed stirring action of the coal powder and the oxygen/oxygen-enriched air, so that the time of the reduction reaction and the steel slag tempering process is greatly shortened, the whole process is 45 min-1.5 h and is far shorter than the hot stuffiness operation period (as long as 23h) of the existing steel slag, and the method is.

In the first step, the pulverized coal 30 is carried by oxygen/oxygen-enriched air 31, a part of the pulverized coal is sprayed into a slag layer in the molten bath of the tempering furnace by a side-blowing coal oxygen lance 33, and a part of the pulverized coal is sprayed into a bottom molten iron layer in the molten bath of the tempering furnace at a high speed by a bottom-blowing coal oxygen lance 32. The side-blown coal oxygen lance 33 sprays the coal powder and oxygen/oxygen-enriched air in the slag layer in the molten bath, and the produced CO reducing gas pre-reduces the laterite-nickel ore entering the furnace, generates a large amount of foam slag and keeps the furnace in a high temperature state all the time. The coal powder sprayed from the bottom reacts with oxygen/oxygen-enriched air in a high-temperature molten pool to obtain CO reducing gas, the CO gas and metal oxides undergo deep reduction reaction, and the metal oxides are completely reduced into metals (Fe, Ni and Cr); in addition, the coal powder injected from the bottom and iron are subjected to a carburizing reaction, so that the melting point of pig iron is reduced, the viscosity of molten iron is reduced, the fluidity is improved, and tapping is facilitated.

Specifically, in the first step, the side-blown coal-oxygen lance is a coal-oxygen sleeve lance (carbon-oxygen molar ratio n)_c：n_o1: 1.1-1.3) and the other important function is to add heat generated by carbon-oxygen reaction in addition to stirring a molten poolIn the middle of the hot melting pool, a large amount of CO floating gas is generated, and the generation of the phenomenon of 'spring' of the melting pool is promoted. In addition, the industrial pure oxygen or oxygen-enriched air blown by the upper layer side coal-oxygen blowing lance and CO gas escaping from the molten pool generate violent oxidation reaction, thereby releasing a large amount of heat energy to heat the foam slag area and the upper part of the molten pool.

Specifically, in the first step, the lower bottom coal-oxygen lance is also a coal-oxygen sleeve lance (carbon-oxygen molar ratio n)_c：n_o1.6-1.8: 1) unlike the upper coal-oxygen blowing lance, the main function of the lance is to blow a large amount of coal powder to provide a reducing agent for smelting reduction, and to ensure the reaction temperature below the molten pool, a certain amount of oxygen is still blown, and the gas product is CO.

Specifically, in the first step, the reduced metals Fe, Ni and Cr are mutually dissolved in a high-temperature smelting pool to form nickel-chromium pig iron.

Specifically, in the first step, the quenching and tempering furnace swings and rotates under the driving of the gear ring of the driving mechanism 28, so that the reduction reaction of iron, nickel and chromium metal oxides in a molten pool and the quenching and tempering process of slag can be accelerated, the materials are distributed more uniformly in the furnace, and the swinging speed is 0.5-1.0 rpm.

Specifically, in the first step, the quenched and tempered pig iron comprises the following components in percentage by mass: fe 88-96%, C1.5-3.5%, Cr1.5-3.5%, Ni1.0-4.0%, S<0.1％，P<0.1% and the balance unavoidable impurities. The slag after quenching and tempering comprises the following components in percentage by mass: 0.9 to 1.5 percent of FeO, 0.01 to 0.03 percent of Cr0.01 to 0.03 percent of Ni0.01 to 0.03 percent of NiO, 1 to 2 percent of FeO, 28 to 48 percent of CaO, SiO₂21％～44％，Al₂O₃3％～7.5％，MgO17％～19％，S<0.1％，P<0.1% and the balance unavoidable impurities.

Specifically, the free CaO, MgO and RO phases in the slag particles in the step two are low, and the content of vitreous bodies in the slag particles is not less than 95%, so that the requirements of cement raw materials are met.

It should be noted that in the first and second steps, the quenching, tempering, reconstructing and modifying principles of the molten liquid steel slag are as follows:

CaO content in the steel slag is 40-60Percent, MgO content 5-10%, alkalinity CaO/SiO₂Generally, the alkalinity is higher than 1.8, the higher the alkalinity is, the higher the free calcium oxide f-CaO is, the alkalinity is 3.1-3.5, and 7-13% of the free calcium oxide f-CaO is usually contained. The steel slag mainly contains free calcium oxide f-CaO and a small amount of free magnesium oxide f-MgO. By adding laterite nickel ore (containing SiO)₂And Al₂O₃) Reconstruction modification, reaction in a molten pool to form calcium aluminosilicate and magnesium aluminosilicate, greatly reducing free calcium oxide and free magnesium oxide in the quenched slag, lowering the melting point and viscosity of the slag, leading the alkalinity to be close to about 1.2 of blast furnace slag, leading the obtained vitreous phase to be more than or equal to 95 percent after water quenching, completely achieving the activity of blast furnace granulated slag, reducing the f-CaO content in the quenched slag to be less than 1 percent and far lower than the f-CaO content in the unprocessed steel slag, and greatly improving the volume stability of the reconstructed steel slag.

FeO and Fe with the total iron content of about 20-25 percent in the steel slag are reduced by coal injection in a molten pool₂O₃Reducing the slag into metallic iron, realizing the separation of the slag and the iron in the tempering furnace, greatly reducing the metallic iron, RO phases (divalent metal oxide continuous solid solution taking MgO and FeO as main components), calcium ferrite and other high-hardness minerals in the steel slag, obviously improving the grindability of the steel slag and solving the key link of the utilization problem of the steel slag. The FeO content in the original steel slag RO phase accounts for 50-60% of the total FeO content in the steel slag, the MgO content in the steel slag RO phase is about 14-20%, and other FeO exists in the silicate, ferrite and iron aluminate phases in a solid solution mode. The majority of the FeO in the steel slag is present in the RO phase. In the reduction and reconstruction process, the injected coal powder has the reduction effect on the iron oxide, and Fe occurs in the occurrence state of Fe element in the reconstruction process³⁺→Fe²⁺Change of → Fe, most of the iron oxides will be reduced to metallic Fe under sufficient reducing agent. Fe during reductive reconstitution²⁺The content of (A) is drastically reduced, FeO in the RO phase is reduced to metallic iron, and the RO phase is decomposed and eliminated. After the addition of the modifying agent, such as laterite-nickel ore, the nickel ore contains rich SiO₂CaO, MgO and Al₂O₃The reduction rate of iron compounds in the steel slag in the tempering furnace is close to 100 percent, and the molten steel slag is reduced, so that more than 90 percent of iron in the steel slag can be recovered, and high-activity steel slag is generatedThe content of glass bodies of the tailings after water quenching is more than or equal to 95 percent, the activity is greatly improved, the content of iron oxide in the tailings is less than 3 percent, and the activity exceeds that of standard cement.

In order to ensure enough waste heat and prevent explosion in the conventional thermal stewing method, the steel slag needs to be tipped into a thermal stewing tank when the steel slag is cooled to 300-800 ℃, a proper amount of water is sprayed to generate saturated steam which reacts with free calcium and magnesium in the slag to generate expansion stress to crush and pulverize the steel slag, and f-CaO and f-MgO in the steel slag are fully digested (the thermal stewing operation period is as long as 23 hours) to form Ca (OH)₂And Mg (OH)₂And finally, the f-CaO content is less than 1.5 percent, so that the stability of the cement is improved. Different from the existing hot-stuffy method, the quenching and tempering process of the invention can mix the quenching and tempering modified material with the high-temperature molten liquid steel slag uniformly under the strong stirring of the jet air flow of the coal-oxygen lance and the swinging of the furnace body, and carry out reduction reaction with the coal-oxygen lance sprayed with the pulverized coal, and can finish the modification purpose of the steel slag on the premise of enough slag temperature (1550-1600 ℃) and reaction time (45 min-1.5 h).

Specifically, in the first step and the second step, the temperature of the flue gas in the tempering furnace is high (1400-1500 ℃), and the high-temperature flue gas is rich in CO reducing gas and needs to be completely burnt in the post-combustion chamber 46, so that the high-temperature flue gas enters the post-combustion chamber 46 through the flue gas outlet cover and the uptake 36, and air is sprayed through the air nozzle 45 to complete CO combustion. The flue gas from the post combustion chamber 46 passes through gravity dust fall 47, enters a boiler membrane wall 48 for heat exchange, and then is subjected to slag condensation through a slag condensation pipe in a waste heat boiler 49, heat exchange through a heat exchange pipe bundle and an economizer to generate steam for power generation and energy recovery. The flue gas with the temperature of 180-200 ℃ coming out of the waste heat boiler 49 is mixed with air through a flue gas temperature adjusting air valve 50 to adjust the temperature, so that the subsequent cloth bags are prevented from being burnt out accidentally, the flue gas with the temperature adjusted and the desulfurizer sprayed in a powder preparation room 51 through an SDS dry desulfurization are desulfurized in a flue gas temperature adjusting/desulfurizing tower 52, the desulfurized flue gas enters a dust collecting cloth bag 54 through a flue 53, and dust in the flue gas is collected through the dust collecting cloth bag 54 and is collected by a dust collecting device 55. The 180-200 ℃ flue gas after dust removal through the dust collection cloth bag is led out by the draught fan 56 and is sent to the drying intervention processing unit (input into the flue gas furnace 14) for recycling through the flue gas circulating waste heat utilization pipeline 57, so that low-temperature waste heat is recycled, drying energy consumption is saved, and the purified surplus flue gas is discharged into the atmosphere through the chimney 58, so that standard discharge is realized.

Specifically, in the first step, in order to prevent moisture in the laterite-nickel ore from being brought into a high-temperature quenching and tempering furnace and avoid safety accidents, the laterite-nickel ore needs to be dried and intervened, a grab bucket machine 7 grabs the laterite-nickel ore into a laterite-nickel ore bin 8 from a laterite-nickel ore storage yard 6, the laterite-nickel ore is input into a crusher 9 through a feeding belt, and the crushed laterite-nickel ore is input into a dryer 11 through a drying and feeding belt 10 to be dried.

It should be noted that the drying energy of the dryer 11 is provided by a flue gas drying furnace 14, the coal gas is combusted with combustion air provided by a coal gas burner 12 and a coal gas burner combustion fan 13 to obtain hot combustion flue gas (the temperature of the hot combustion flue gas is greater than 1000 ℃), the hot combustion flue gas in the flue gas furnace 14 is input into the dryer 11, the hot combustion flue gas and the water-containing modifying agent perform gas-solid two-phase heat exchange, and the modifying agent is dried to 110-120 ℃. The dried modifying agent is sent into a furnace cache bin 25 to be used as the modifying agent for standby. The waste drying flue gas of the dryer 11 is desulfurized in the drying flue gas desulfurization tower 20, then is dedusted by the drying flue gas deduster 21, and is introduced into the drying flue gas chimney 23 by the drying flue gas induced draft fan 22 to achieve standard emission. Specifically, in order to save energy consumption, the flue gas at 180-200 ℃ after dust is collected by the dust collecting bag is input into the flue gas furnace 14 to be used as part of drying energy.

Compared with the prior art, the method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore fully utilizes the sensible heat of the high-temperature molten steel slag at 1550-1600 ℃ (reduced to 55-61 kg standard coal/t-steel slag), and reduces the energy consumption required by reduction of metal oxides and quenching and tempering modification of the steel slag in a quenching and tempering furnace; by blowing coal powder and oxygen/oxygen-enriched air into the tempering furnace, iron, nickel and chromium oxides in the steel slag and the laterite-nickel ore are subjected to violent reduction reaction in a molten pool and are converted into nickel-chromium alloy, so that the complete recovery (more than 95%) is realized, the nickel-chromium alloy pig iron can be directly used for steelmaking in a rotary furnace, not only is the iron resource in the steel slag completely recovered, but also a large amount of iron, nickel and chromium resources in the laterite-nickel ore are synchronously recovered. Free CaO, MgO and RO phases are not contained in the slag after tempering and reconstruction of CaO, SiO and MgO rich in the laterite nickel ore and steel slag, the slag after tempering and reconstruction can be used in the field of cement concrete without being limited by the application range, the free CaO, MgO and RO phases in the steel slag are completely converted into active minerals, the activity of the slag after tempering is high (more than S95 grade), and the comprehensive utilization rate of the steel slag reaches 100 percent.

According to the method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore, the utilization rate of the residual heat of the molten steel slag is high, the molten steel slag at 1550-1600 ℃ is smelted with the laterite-nickel ore in a quenching and tempering furnace, the steam is recovered from the high-temperature flue gas residual heat after quenching and tempering through a residual heat boiler to generate power, the flue gas at 180-200 ℃ after dust removal is circulated to a dryer, the consumption of drying coal gas is reduced, and the residual heat resource is fully utilized.

The method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore has the advantages of short operation period, completion of the quenching and tempering process for 45 min-1.5 h and high efficiency.

Example one

In the embodiment, for example, the steel scale of 400 ten thousand tons produced in a certain steel plant every year is 40 ten thousand tons, the average slag quantity of the steel slag is 47.62t/h, a hot slag disintegrating method is originally adopted, the slag utilization rate is about 20%, the steel slag is quenched and tempered by adopting the method for the synergistic quenching and tempering of the steel slag and the laterite-nickel ore, and the 1# high-nickel low-iron laterite-nickel ore is added as a quenching and tempering agent.

Pouring liquid molten steel slag (enthalpy is about 56kg standard coal/t-slag) at 1550-1600 ℃ into a quenching and tempering furnace, adding dried 1# high-nickel low-iron laterite-nickel ore (water content is less than 1%), and carrying out quenching and tempering for 60 min. The quenching and tempering process uses total oxygen or oxygen-enriched air as a carrier, and coal powder is sprayed in by adjusting a bottom coal-blowing oxygen lance and a side coal-blowing oxygen lance. In general, bottom blowingCoal-oxygen lance (n)_c：n_o1.6-1.8: 1) side-blown coal oxygen lance (n)_c：n_o1: 1.1-1.3), and the blowing speed is 100-150 m/s, so that the iron oxides in the steel slag and the No. 1 high-nickel low-iron laterite-nickel ore are reduced. The high-temperature liquid nickel-chromium alloy pig iron after quenching and tempering enters an iron casting machine from an iron runner or is transported to steel making by a hot metal ladle from an iron tap hole for producing stainless steel or corrosion-resistant steel. Discharging the quenched slag into a slag flushing channel through a slag outlet, flushing the slag with flushing water to obtain water-quenched slag, and conveying the water-quenched slag to a slag treatment workshop for fine grinding to be used as a cement admixture. And (3) spraying air to 1400-1500 ℃ high-temperature flue gas in the tempering furnace through a afterburning chamber to burn out residual CO gas, recovering flue gas waste heat by using a boiler, generating steam by using the waste heat and generating electricity, removing dust from the flue gas discharged from the waste heat boiler through a dust collecting cloth bag, collecting 180-200 ℃ flue gas discharged from the dust collecting cloth bag, and recycling the flue gas for drying the tempering agent 1# high-nickel low-iron laterite-nickel ore.

Table 1 shows the components and the processing amount of the quenching and tempering agent for the molten steel slag and the No. 1 high-nickel low-iron laterite-nickel ore; as can be seen from Table 1, 40 ten thousand tons of steel slag and 46 ten thousand tons of No. 1 high-nickel low-iron laterite-nickel ore are processed according to the year, the total weight is 86 ten thousand tons, the total iron content in the steel slag is 20.88 percent, the total iron content in the No. 1 high-nickel low-iron laterite-nickel ore is 13.21 percent, iron oxide is reduced into liquid metal iron through a quenching and tempering furnace molten pool (1550-1600 ℃), and the yield of the iron metal is 96.16 percent.

TABLE 1 Steel slag and No. 1 high-nickel low-iron laterite-nickel ore conditioner composition and treatment amount

Table 1 steel slag and 1# high-nickel low-iron laterite-nickel ore conditioner composition and treatment amount

Table 2 shows the composition and amount of the quenched and tempered pig iron and the quenched and tempered slag; 15.5 ten thousand tons of nickel-chromium alloy pig iron and 58.39 ten thousand tons of quenching and tempering slag are produced in the year after quenching and tempering treatment.

TABLE 2 composition and yield of nickel-chromium alloy pig iron, slag after thermal refining of steel slag and No. 1 high-nickel low-iron laterite-nickel ore

Table 3 shows the income of the quenched and tempered steel slag and 1# high-nickel low-iron laterite-nickel ore, and the total annual income can reach 10.856 million yuan according to the current product price shown in Table 3.

TABLE 3 Steel slag and No. 1 high-nickel low-iron laterite-nickel ore after thermal refining

The raw fuel cost of the quenching and tempering treatment is shown in Table 4, the total annual treatment cost is 3.108 hundred million yuan, the raw fuel cost per unit product (pig iron and slag) is 420.64 yuan, and the raw fuel cost per ton of nickel-chromium alloy pig iron is 2004.83 yuan.

TABLE 4 cost of raw fuel for thermal refining of steel slag and 1# high-nickel low-iron laterite-nickel ore

The energy consumption of the quenching and tempering process of the steel slag and the No. 1 high-nickel low-iron laterite-nickel ore is shown in the table 5, and based on the total product, the energy consumption of the waste heat steam recovered is used as a deduction item, the energy consumption is reduced to 87.97kg standard coal in the process of ton products (pig iron and slag), the energy consumption is reduced to 419.27kg standard coal in the process of ton iron according to the conversion of nickel-chromium alloy pig iron, and the energy consumption is only equivalent to about 87.3 percent of the energy consumption (480kg standard coal) in the process of blast furnace molten.

TABLE 5 energy consumption of quenching and tempering process of steel slag and No. 1 high-nickel low-iron laterite-nickel ore

(1) The conventional 1# high-nickel low-iron laterite-nickel ore direct reduction + electric furnace smelting cost and energy consumption are as follows:

1) cost analysis

The direct reduction cost of the broken ton nickel-chromium pig iron is as follows: 2033.75 yuan/t-iron;

melting cost of a ton-folded nickel-chromium pig iron electric furnace: 3364.62 yuan/t-iron;

total ton of nickel chromium pig iron cost: 5398.37 yuan/t-Fe.

2) Energy consumption analysis

Energy consumption of direct reduction of broken-ton nickel-chromium pig iron: 543.63kg standard coal/t-iron

Melting and separating energy consumption of a ton-folded nickel-chromium pig iron electric furnace: 865.8kg standard coal/t-iron

Total ton energy consumption of nickel-chromium pig iron: 1409.43kg standard coal/t-iron

(2) The conventional 1# high-nickel low-iron laterite-nickel ore small blast furnace smelting cost and energy consumption are as follows:

cost per ton of nickel-chromium pig iron: 4088.82 yuan/t-iron;

energy consumption of broken ton of nickel-chromium pig iron: 1694.05kg standard coal/t-iron

Example two

Referring to table 6, in the embodiment, 40 ten thousand tons of steel slag and 46 ten thousand tons of 2# low-nickel high-iron laterite-nickel ore are processed annually, the total iron content is 86 ten thousand tons, the total iron content in the steel slag is 20.88%, and the total iron content in the 2# low-nickel high-iron laterite-nickel ore is 44.58%.

TABLE 6 Steel slag and No. 2 low-nickel high-iron laterite-nickel ore compositions and treatment amounts

Table 6 steel slag and 2# low-nickel high-iron laterite-nickel ore compositions and treatment amounts

Table 7 shows the composition and amount of quenched and tempered pig iron and quenched and tempered slag; 29.57 ten thousand tons of nickel-chromium pig iron and 43.54 ten thousand tons of quenched and tempered slag are produced annually after quenching and tempering.

TABLE 7 Nichrome pig iron, slag components and product yields after thermal refining of steel slag and 2# low-nickel high-iron laterite-nickel ore

As can be seen from Table 8, the annual total income can reach 10.61 billion yuan in accordance with the current product price.

TABLE 8 Steel slag and No. 2 low-nickel high-iron laterite-nickel ore quenching and tempering product income

The raw fuel cost of the quenching and tempering treatment is shown in Table 9, the total annual treatment cost is 2.56 million yuan, the raw fuel cost per unit product (pig iron and slag) is 350.17 yuan, and the raw fuel cost per ton of nickel-chromium pig iron is 865.86 yuan.

TABLE 9 cost of raw fuel for thermal refining of steel slag and No. 2 low-nickel high-iron laterite-nickel ore

The energy consumption of the quenching and tempering process is shown in a table 10, wherein the energy consumption of the waste heat steam recovered is used as a deduction term according to the total product, the energy consumption is reduced to 115.21kg standard coal in the process of ton products (pig iron and slag), the energy consumption is reduced to 284.89kg standard coal in the process of ton iron according to the conversion of nickel-chromium pig iron, and the energy consumption is only equivalent to about 59.35 percent of that of the process of blast furnace molten iron.

TABLE 10 energy consumption of quenching and tempering process of steel slag and No. 2 low-nickel high-iron laterite-nickel ore

(1) The conventional 2# low-nickel high-iron laterite-nickel ore direct reduction + electric furnace smelting cost and energy consumption are as follows:

1) cost analysis

The direct reduction cost of the broken ton nickel-chromium pig iron is as follows: 1020.01 yuan/t-iron;

melting cost of a ton-folded nickel-chromium pig iron electric furnace: 1710.47 yuan/t-iron;

total ton of nickel chromium pig iron cost: 2730.48 yuan/t-Fe.

2) Energy consumption analysis

Energy consumption of direct reduction of broken-ton nickel-chromium pig iron: 511.85kg standard coal/t-iron

Melting and separating energy consumption of a ton-folded nickel-chromium pig iron electric furnace: 679kg Standard coal/t-iron

Total ton energy consumption of nickel-chromium pig iron: 1190.85kg standard coal/t-iron

(2) The conventional 2# low-nickel high-iron laterite-nickel ore small blast furnace smelting cost and energy consumption are as follows:

cost per ton of nickel-chromium pig iron: 2086.19 yuan/t-iron;

energy consumption of broken ton of nickel-chromium pig iron: 1108.7kg standard coal/t-iron

From the above, by adopting the method for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore, the high-temperature sensible heat of the steel slag is utilized, the defects of high energy consumption, poor raw material adaptability, low metal recovery rate and the like of the traditional nickel-chromium alloy smelting process by using the laterite-nickel ore are overcome, the iron resource and other metal resources of the laterite-nickel ore can be recovered, and the problem of poor activity of the steel slag is solved. The nickel-chromium alloy pig iron product after quenching and tempering completely meets the steel-making requirement, can be used for producing stainless steel and corrosion-resistant steel, and slag after quenching and tempering meets the requirement of building materials and can be utilized by 100 percent.

The processing energy consumption and the raw fuel cost of the method for the synergistic thermal refining of the steel slag and the laterite-nickel ore are far lower than those of the traditional process, and the comprehensive benefit is far higher than that of the prior processing technology.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. The device for the cooperative quenching and tempering treatment of the steel slag and the laterite-nickel ore is characterized by comprising a quenching and tempering furnace and a driving mechanism (28), wherein the quenching and tempering furnace comprises a quenching and tempering furnace molten pool (27), a steel slag feeding hole (26) and a laterite-nickel ore feeding hole are formed in the upper part of the quenching and tempering furnace, and a coal-oxygen lance is further arranged on the quenching and tempering furnace; the driving mechanism (28) is arranged at the bottom of the hardening and tempering furnace and is used for driving the hardening and tempering furnace to rotate and swing;

the steel slag handling device further comprises a molten steel slag handling unit used for transferring the molten steel slag.

2. The device for the cooperative hardening and tempering of the steel slag and the lateritic nickel ore according to the claim 1, further comprising a riding wheel mechanism (29), wherein the riding wheel mechanism (29) is used for supporting a hardening and tempering furnace.

3. The device for the cooperative hardening and tempering of the steel slag and the laterite-nickel ore according to claim 2, characterized in that the number of the riding wheel mechanisms (29) is two, and the two sets of the riding wheel mechanisms (29) are symmetrically distributed at the bottom of the hardening and tempering furnace.

4. The device for the cooperative hardening and tempering treatment of the steel slag and the lateritic nickel ore according to the claim 1, wherein the coal-oxygen lance comprises a bottom-blowing coal-oxygen lance (32) and a side-blowing coal-oxygen lance (33), and a plurality of the bottom-blowing coal-oxygen lances (32) are arranged at the bottom of a hardening and tempering furnace; a plurality of side-blown coal oxygen lances (33) are arranged on the side wall of the tempering furnace.

5. The device for the cooperative quenching and tempering of the steel slag and the lateritic nickel ore according to the claim 1, characterized in that both ends of the quenching and tempering furnace are respectively provided with a slag outlet (35) and a tap hole (34).

6. The device for the cooperative thermal refining of the steel slag and the lateritic nickel ore according to the claim 1, further comprising a pig iron casting and collecting unit (f), a slag processing unit (c) after thermal refining and a flue gas processing unit (b) of a thermal refining furnace.

7. The method for the cooperative quenching and tempering of the steel slag and the laterite-nickel ore is characterized by comprising the following steps of:

step three: the coal powder (30) is sprayed into a tempering furnace by taking oxygen/oxygen-enriched air (31) as a carrier, and is subjected to tempering treatment to obtain tempered slag and high-temperature molten iron.

8. The method for the cooperative quenching and tempering treatment of the steel slag and the lateritic nickel ore according to the claim 7, characterized in that in the third step, a part of the coal dust is sprayed into the bottom molten iron layer in the quenching and tempering furnace molten bath at a high speed through a bottom blowing coal oxygen lance (32), and the other part of the coal dust is sprayed into the slag layer in the quenching and tempering furnace molten bath through a side blowing coal oxygen lance (33) to carry out the quenching and tempering treatment.

9. The method for the cooperative hardening and tempering treatment of the steel slag and the lateritic nickel ore according to claim 7, wherein in the hardening and tempering treatment process, the hardening and tempering furnace is driven by a driving mechanism to swing in a rotating manner.

10. The method for the cooperative hardening and tempering treatment of the steel slag and the lateritic nickel ore according to the claims 7 to 9, characterized by further comprising the following steps:

adjusting the quenching and tempering furnace to a tapping position, and discharging high-temperature molten iron from a tapping hole (34); then, the tempering furnace is adjusted to a slag discharging position, and slag after tempering is discharged from a slag discharging hole (35).