The method and apparatus of a kind of calcining, thermal reduction refining magnesium
Technical field
The present invention relates to the method and apparatus of a kind of calcining, thermal reduction refining magnesium, belong to Industrial Stoves and light-weight metal metallurfgy technical field.
Background technology
Smelting magnesium by thermal reduction process is one of method of production MAGNESIUM METAL, is raw material with rhombspar, wagnerite etc. mainly, is sintered into magnesium oxide in kiln, adds reductive agent then and heats in thermal reduction furnace and be reduced into MAGNESIUM METAL.The domestic Pidgeon process technology refining magnesium that generally adopts, be raw material promptly with the rhombspar (MgO, CaO) after the calcining, with ferrosilicon (Si-Fe) is reductive agent, mix by a certain percentage and wear into fine powder, be pressed into agglomerate, put into the reduction jar, in thermal reduction furnace, add thermal reduction and obtain magnesium steam, condensation-crystallization becomes solid-state magnesium, is melt into magnesium ingot again.The advantage of this method is that method is simple, and its weak point is that energy consumption is too high.Calcined dolomite and thermal reduction refining magnesium process all is at high temperature to carry out, and longer duration needs to consume a large amount of coal or fuel gas, and two processes carry out respectively, has strengthened the consumption and the tooling cost of magnesium production process fuel like this.
Being authorized notification number provides " a kind of energy-conservation MAGNESIUM METAL thermal reduction furnace " for the Chinese patent of CN201003068Y, and coal is fully burnt, and improves the intravital temperature of stove, reduces dust and exhaust emission.But this patent can not solve the high-temperature flue gas that thermal reduction furnace comes out and utilize problem, so degree of power conservation is restricted.The applicant is to disclose " a kind of method of calcining materials and vertical kiln apparatus thereof " in 200810054931.4 the application for a patent for invention at number of patent application, the vertical kiln apparatus that is provided is the limestone kiln structure of peripheral hardware roasting kiln, and the flue gas line at kiln body top is connected to blowdown system by airtight feeding line; The products export of kiln body bottom is communicated with airtight tapping channel, and burner blower is connected to roasting kiln combustion air inlet through tapping channel.This patent application utilizes the smoke pre-heating material of kiln, makes combustion air with the warm air behind the chilled product, has solved the problem that calcined limestone, rhombspar process waste heat utilize, and makes full use of heat, and fuel saving reduces exhaust gas emission.But this patent application does not propose a plan to the utilization of thermal reduction process waste heat, can not solve the excessive problem of energy expenditure in the smelting magnesium by thermal reduction process process.
Summary of the invention
For solving the high problem of smelting magnesium by thermal reduction process process energy expenditure, the invention provides the method and apparatus of a kind of calcining, thermal reduction refining magnesium, make thermal reduction refining magnesium and the combination of calcined dolomite process optimization, the waste heat of generation is fully used, reduce energy expenditure, reduce production costs.
The method of calcining provided by the invention, thermal reduction refining magnesium is, with the kiln calcined dolomite of calcining materials, refines MAGNESIUM METAL with thermal reduction furnace, and the flue gas that comes out from thermal reduction furnace feeds the calcining zone of kiln, is used for calcined dolomite.
The device of calcining of the present invention, thermal reduction refining magnesium includes kiln and at least one thermal reduction furnace of calcining materials, the reduction jar is housed in the thermal reduction furnace, kiln has preheating zone, calcining zone and cooling zone, and the exhanst gas outlet of thermal reduction furnace is connected to the calcining zone of kiln.The fuel that thermal reduction furnace uses is solid fuel, liquid fuel, geseous fuel or its combination.
Be Optimizing operation, described thermal reduction furnace exhanst gas outlet is connected to the calcining zone of kiln through gravitational precipitator and temperature regulation stove.The temperature regulation stove is equipped with burner and gas inlet, is used to regulate the temperature of flue gas to adapt to the needs of calcining materials.Described burner is solid fuel burner, liquid fuel burner, geseous fuel burner or its combination.Described kiln is shaft furnace or rotary kiln or fluidized bed calcination stove, does not get rid of the kiln of other type.The calcining zone of described shaft furnace is provided with peripheral burner, and the quantity of peripheral burner is determined according to the size of kiln.
For making device operation and heat coupling continuously, the device of described calcining, thermal reduction refining magnesium is provided with a kiln and 2~5 thermal reduction furnaces, the exhanst gas outlet of thermal reduction furnace is connected in parallel together, and process gravitational precipitator and temperature regulation stove are connected to the calcining zone of kiln.Every thermal reduction furnace exhanst gas outlet pipeline is provided with valve.
For utilizing the heat of kiln waste gas and warm air, the offgas line of kiln is connected to chimney through thermal reduction furnace fuel interchanger and/or air heat exchanger; Warm air line behind the kiln chilled product is connected to chimney through thermal reduction furnace fuel interchanger and/or air heat exchanger.The another program that utilizes using residual heat from kiln furnace is connected to the combustion air line of thermal reduction furnace for gas blower by the reactor product cooler of kiln, makes the combustion air of thermal reduction furnace with the warm air of chilled product.
Compared with prior art, advantage of the present invention is to have realized optimizing integration of smelting magnesium by thermal reduction process and calcined dolomite, and the heat that thermal reduction refining magnesium and calcined dolomite process produce is fully used fuel saving about 30~40%; Device is compact, and floor space is little; Many thermal reduction furnace parallel operations can move continuously, and the shaft furnace calcining zone is provided with peripheral burner, additional heat as required, and flexibility of operation is good.
Description of drawings
Fig. 1 is calcining of the present invention, thermal reduction magnesium smelting device synoptic diagram;
Fig. 2 is a heat exchange process synoptic diagram of the present invention;
Fig. 3 regulates the stove synoptic diagram for the present invention;
Fig. 4 is for another program of the present invention is calcined, thermal reduction magnesium smelting device synoptic diagram;
Fig. 5 is shaft furnace of the present invention and four calcining, thermal reduction magnesium smelting device synoptic diagram that thermal reduction furnace is formed.
Embodiment
The present invention is further illustrated below in conjunction with accompanying drawing.
Embodiment 1
Present embodiment as shown in Figure 1 and Figure 2, device for beam type shaft furnace and thermal reduction furnace formation includes thermal reduction furnace 4 and kiln 1, and thermal reduction furnace is equipped with reduction jar 5, the reduction jar is made with the thermochronix steel, and thermal reduction furnace is provided with fuel burner nozzle and solid fuel burner; Divide preheating zone, calcining zone and cooling zone in the kiln, top, preheating zone is provided with suction bar 9, and calcining zone is provided with air inlet beam 10, and the middle part of cooling zone is provided with down suction bar 11.The exhanst gas outlet on thermal reduction furnace top is connected to the air inlet beam 10 of kiln 1 calcining zone through gravitational precipitator 3 and temperature regulation stove 2.As shown in Figure 3, the temperature regulation stove is equipped with burner 16 and gas inlet 15, the temperature that is used to regulate flue gas.The fuel that the temperature regulation stove uses is geseous fuel, also can use solid fuels such as coal dust.When the flue-gas temperature of coming out from thermal reduction furnace is lower than the desired temperature of calcined dolomite, open burner 16 burnings, make flue-gas temperature reach calcining temperature; When flue-gas temperature is higher than the needed temperature of calcined dolomite, open gas inlet 15, bubbling air reduces flue-gas temperature, in case material burning in the kiln 1.Thermal reduction furnace 4, kiln 1, temperature regulation stove 2 and connection line all are steel construction, inner lining as thermal insulation material and refractory brick.
As shown in Figure 2, last suction bar 9 is connected to air heat exchanger 12, is connected to chimney 14 through fly-ash separator 21, induced draft fan 22 then; Following suction bar 11 is connected to chimney through fuel interchanger 13, fly-ash separator and induced draft fan.Air line enters the mouth 7 through the combustion air that air heat exchanger 12 is connected to thermal reduction furnace burner place, and the fuel line is connected to thermal reduction furnace fuel inlet 6 through fuel interchanger 13.
The method of calcining, thermal reduction refining magnesium is, fuel burn in thermal reduction furnace 4 and adds thermal reduction jar 5 refining MAGNESIUM METAL, and fuel used is geseous fuel or solid fuel, or while using gas fuel and solid fuel.The high-temperature flue gas that produces is gone out from the thermal reduction furnace exhanst gas outlet, through gravitational precipitator 3 and temperature regulation stove 2, enter the calcining zone calcined dolomite of kiln 1 by air inlet beam 10, flue gas leaves calcining zone upwards enters kiln through the preheating zone preheating rhombspar, enters suction bar 9 then.The waste gas that leaves kiln is through the combustion air heat exchange of air preheater 12 with thermal reduction furnace.The warm air of another road behind the chilled product of the cooling zone of kiln 1 passes through suction bar 11 down, and through fuel interchanger 13 and fuel heat exchange, two-way is joined and discharged atmosphere through fly-ash separator 21, induced draft fan 22 to chimney 14 then.The calcining zone of shaft furnace is provided with peripheral burner 23, opens the burner additional heat during in order to the flue gas heat deficiency, and the fuel that peripheral burner uses is geseous fuel.Also can select to open burner 16 or air 15 according to the temperature requirement of thermal reduction furnace flue-gas temperature situation and calcining materials.
Embodiment 2
Another embodiment of the present invention includes thermal reduction furnace 4 and rotary kiln 19 as shown in Figure 4.The thermal reduction furnace exhanst gas outlet is connected to the high-temperature gas inlet 20 of rotary kiln 19 calcining zones through gravitational precipitator 3, temperature regulation stove 2.Gas blower 18 is connected to the combustion air inlet 7 of thermal reduction furnace 4 through the reactor product cooler 17 of rotary kiln.The high-temperature flue gas that thermal reduction furnace refining magnesium produces enters the calcined by rotary kiln rhombspar, flue gas leave the kiln body behind the feed preheater preheating rhombspar raw material by smoke stack emission.According to the needs of rotary kiln 19 calcined dolomite temperature, regulate the temperature that enters the rotary kiln flue gas with temperature regulation stove 2.Warm air behind the reactor product cooler 17 cooling calcined dolomite products of rotary kiln 19 enters thermal reduction furnace 4 combustion airs inlet 7 as combustion air.The fuel that present embodiment thermal reduction furnace 4 and temperature regulation stove 2 use is coal dust.
Embodiment 3
Third embodiment of the invention includes four thermal reduction furnaces 4 and a kiln 1 as shown in Figure 5.The exhanst gas outlet of four thermal reduction furnaces is connected in parallel together, passes through gravitational precipitator 3 then, and temperature regulation stove 2 is connected to the calcining zone of kiln 1.On every thermal reduction furnace exhanst gas outlet pipeline valve 8 is housed, can turns off valve when a thermal reduction furnace charging or discharging, disconnection is connected with system, and other several thermal reduction furnaces are guaranteed the continuity of device operation still in operation.