Vanyukov furnace for melting materials containing non-ferrous and ferrous metals

FIELD: heating.

SUBSTANCE: invention relates to metallurgy branch and particularly to oxidized nickel ore processing to matte or ferronickel. Vanyukov furnace contains coffered well, which is rectangular at bottom and expanding in top part and separated by cross wall into melting and reduction chambers, staggered or tilted hearth, siphon with openings for sludge and metal containing phase discharge. Tuyeres are displaced along periphery of well walls. Chambers contact between each other through the window for melt flowing in low part of cross wall. Furnace is provided with tuyere adjusting melt flow volume through window for melt flow and its heating. It is located under the level of the said tuyeres by 5-8 diameters of their aperture. Rectangular walls of melting and reduction chambers of furnace are lined and conjugated along the whole height of cross wall through temperature compensated vertical clearances closed by coffered part of well walls from one side and by cross wall end from the other side. Cross wall is made high-refractory. Invention ensures increase of operation duration or reliable operation due to exclusion of crust formation in melt flow window from one chamber to another and avoidance of lining damage in rectangular part of furnace well and reduction of coolants flow rate.

EFFECT: increase of operation duration and improvement of reliable operation due to exclusion of lining damage in rectangular part of furnace well and reduction of coolants flow rate.

2 dwg

The invention relates to metallurgy, in particular to a device for the continuous processing of oxidized Nickel ores, slag and dust.

Currently, these types of metallurgical raw materials processed in shaft kilns. The shaft furnace is a rectangular tank - mine, in which top load Kuskovo oxidized ore, fluxes and coke. In the lower part of the side walls have openings for supplying air into the layer of solid preheated coke. The products of combustion of coke is heated and melted charge, which flows down and out of the furnace through the hole located at the bottom. External sump melt into slag and matte (ferronickel). Disadvantages mine smelting are complex and expensive preparation of the mixture to heat (briquetting, rolling and agglomeration), use as fuel only lumpy expensive coke; removal of dust from the exhaust gases exceeds 10% by weight of the charged metal and the emissions of more than 50% of the sulfur contained in sulfidization used to get the matte. All this taken together makes mine smelting environmentally unsound and economically unprofitable.

Known furnace for continuous melting of sulfide materials in a liquid bath containing melting and recovery areas separated water cooled the partition, with lower flow. In the recovery chamber of this 2-zone furnace installed electrodes, the formation area of the arc which is served by natural gas (the magazine "Nonferrous metals" No. 3, p. 24, 2003). The disadvantage of this offer similar Vanyukov furnace is that the lower the flow or window for flow of melt from one area to another quickly clogged due to cooling of the walls of the box, and the presence of electrodes in the bath with connecting zones and metal (copper) elements of design, through the molten metal, creates a great danger to the service personnel and provides a large leakage current. For this reason, this oven has not found its industrial applications.

Known Vanyukov furnace for continuous melting of materials containing non-ferrous and ferrous metals (RF patent No. 2242687 on application No. 2003111724 from 22.04.2003, prototype). The prototype has a rectangular bottom and extending in the upper part of the caisson shaft with lances, transverse partitions dividing the furnace into chambers oxidative melting of charge and recovery of oxides of the slag, stage furnace hearth, a siphon for the production of slag, the channel for the release of metal or matte, boreholes for emergency release melts, internal siphon for overflow of liquid slag from the camera oxidative melting in the upper part of the chamber recovery of oxides of the slag, the ducts for the exhaust gases and the cameras, device to download content.

The disadvantage of the prototype is that during melting of solid materials on matte or ferronickel produced in the melting chamber or loaded into this camera the melt (for example, hot slag from the shaft furnace) is sent to the window transverse partitions in a thin layer and freezes, blocking the window for flow of melt through the intermediate siphon in the recovery chamber. This in turn leads to the filling of the melting chamber to the upper edges of the transverse partitions and the coal loaded into the melting chamber, entrained slag in the camera repair, thereby causing a disturbance in the melting chamber of the ratio carbon/oxygen and heat balance of the specified process regulations. As a result of this occurs periodically cooling of the slag and its freezing in the melting zone with the termination of the heat. Industrial testing and use of this furnace ("Black metal", "Nonferrous metals", s-94, 2005, special edition) also showed that is possible to operate the furnace at a solidification of the melt in the window overflow, but when this takes place: the uncontrolled transfer of coal from the melting chamber through the upper edge of the transverse partition in recovery, a considerable shift of the horizontal forces acting on the wall (possibly the destruction of the lane the villages and accelerated wear of the cooling copper caissons, forming the upper edge of the transverse septum, followed by the possible explosion due to breakthrough of water from these caissons in the melt). In addition, when testing 2-zone Vanyukov furnace (prototype) in industrial conditions were identified another significant disadvantage is that the lining in the lower zones of the walls of the furnace (prototype) under the influence of thermal deformation forces periodically barred from carrying metal wall and falls down inside the furnace, thereby disrupting the efficiency of the furnace.

The proposed new furnace design provides the following technical results. It also creates an opportunity: if not full, then multiple reduce the likelihood of a breakthrough of water into the melt of the cooling panels of the top row partitions; stabilization of the level of the melt in the melting chamber at various specified values

of the conditions under which the transfer of carbon-containing material through the upper edge of the partition in recovery; regulation ratio carbon/oxygen and maintain stable thermal balance; the exclusion of the destruction of the furnace lining and partitions due to the influence of unsteady forces of thermal deformation of the lining materials.

The above technical result of the invention is achieved in that in the known furnace for continuous melting of materials, sod is rasih ferrous and non-ferrous metals, including mine with a caisson and is lined with refractory material wall, the camera oxidative melting and camera recovery of oxides of the slag, a transverse partition with window for flow of melt from the camera oxidative melting into the camera recovery of oxides of the slag, provided with a side wall tuyeres mine, stage furnace hearth, the siphon with holes for the release of the slag and metal phases, the window for flow of the melt contains a lance cooled or uncooled, and the ends lined the walls of each chamber are interfaced through thermocompensation vertical clearances over the entire height of the transverse partitions, closed on one side caisson wall of the mine and with the other end of the high strong refractory transverse partitions with cooling elements or without them.

In addition, the gaps are filled with granules of the slag melt, and the width of the lower part of transverse bulkhead shall be not less than (1,6÷2,0)·K, where K is the maximum linear size increase (thermal expansion horizontally) futureuse wall at a maximum temperature in the chambers of the furnace.

Figure 1 - the proposed furnace, a longitudinal section and figure 2 is a fragment of the cross section a-a cross partitions.

The furnace includes a rectangular bottom and extending in the upper part of the caisson shaft 1 with lances 2, 3, 4, p is pepper the partitions 5, 12 (partition 12 may be absent in some cases), separating the furnace into chambers oxidative melting of charge 6 and the recovery of oxides of the slag 7, stage furnace hearth 8, a siphon for the production of slag 9, the channel for the release of metal or matte 10, the holes for the emergency release of the melt 11, an internal siphon 13 for overflow of liquid slag from the camera oxidative melting in the upper part of the chamber recovery of oxides of the slag, flue 14 to exhaust gases from the chamber recovery, flue 17 for removal of gases from the chamber oxidative melting 15, a hole 18 for the production of slag from the camera 7, the lance 20 to adjust the level of the melt in the melting chamber 6, located in box 19 of the flow of melt from the chamber 6 into the trap 13, the gaps 21 to compensate for thermal expansion high strong refractory lining.

The lance 20 is located below the level of the tuyeres 3 5÷8 diameters (d) of the hole of the mouth of the tuyere 3. When the depth of the location of the tuyere 20 below 18 hole diameters d of the mouth of the tuyere 3 possible occlusion of the mouth of the tuyere 20 residual streams of melt flowing from the walls of the shaft furnace and partitions 5, decreasing to 14·d reduces the lifetime of the code peritoneo window 19 of the appearance of a rotating hydrodynamic flow around the inner perimeter of the window 19, i.e. the emergence of "strong abrasive effect (the Study of the mechanism of interaction is submerged gas jets with the melt, "Non-ferrous metals", No. 3, 2003, pp.33-36).

The oven works as follows.

The charge flux additives and solid fuel load through the device 15 to the surface Bartiromo blown slag melt in the camera oxidation of the melt 6. The splashing of the melt and the oxidation of the carbonaceous fuel is carried out by supplying the oxygenated melt blown through tuyeres 3 in the side walls of the furnace in an amount necessary for complete combustion of combustible components with maximum heat. Due to the intensive mixing and heat of combustion of the solid fuel charge quickly melts and forms a homogeneous slag, which as it accumulates at the bottom edge of the partition 5, through the window 19 and the inner siphon 13 flows into the upper part of the chamber recovery 7.

The presence of the lance 20 in peritoneum window 19 and above its location allows you to create a pulsating mode of flow (due to the interaction of the flame with the melt) melt from the melting chamber 6 in the recovery 7 and to adjust the speed and the power flow of the melt flowing through the window 19, by changing the configuration of the torch lance 20 and the differential level of the melt in these cells. In the simplest case, such a change or regulation carried out by changing the flow rate (pressure) of the gas stream at the mouth f rmy 20.

Here we note in particular that the possibility of the described regulation of the flow of melt through the window 19 also provides automatic regulation of the level in the melting chamber 6 in accordance with the requirements of technological regulations on the processes of melting different composition of materials in Vanyukov furnace. One of the main requirements of the regulations - minimum or complete elimination of a transfer of slag from coal through the upper edge of the transverse partition 5. The adjustment range is chosen, using known methods of selecting the number froda (where υ₀the flow rate of gases at the nozzle exit diameter d₀; g - acceleration of free fall) for submersible torches. It should also be noted that the vector of the resulting melt flow in peritoneum window will always be directed towards the recovery chamber 7 due to the differential between the chambers 7 and 6, and the possible cooling of the weak flow of the melt or freeze them in start-up mode is excluded, since both the change in the power flow of the melt is the change of the heat flow in the window 19 by regulating the heat in peritoneum box 19 through the previously described configuration changes torch on the nozzle of the lance 20. For more reliable operation of large-scale furnaces, obviously, should be increased : the window 19 to 2 (with the location of them on the ends of the partitions 5).

In camera recovery of oxides of the slag through the loading device 16 in the upper part Bartiromo melt is injected solid carbonaceous materials such as coal and, if necessary, the material balance of melt, additional fluxing materials, including sulfidization. Coal is injected in an amount necessary to restore the recoverable metal oxides and thermal compensation costs. The splashing of the melt to accelerate heat and mass transfer and oxidation of the fuel to the required content of carbon monoxide (CO) and hydrogen in the chemical reaction zone in the melt support by supplying oxygen-containing blast through a number of lances 2. In the reduction reactions and if necessary, sulfatirovnie in the chamber restore is formed of metal or sulfide phase, droplets which fall to the bottom of the camera recovery and release from the furnace through the channel 10 or through the borehole 11. Slag, depleted for non-ferrous and iron, are produced through a window 18 in the siphon 9. Gases camera recovery containing CO and H₂to save fuel and reduce their toxicity dorogaya, feeding oxygen-containing blast through a number of lances 4. After post-combustion gases is removed from the oven for cleaning dust and waste heat through the flue 14 or 17 or simultaneously through 14 and 17.

It is known that will restore the selected processes in the range of iron content in the slag 8-20% occurs foaming of the slag and the slag foam can reach the vault, to seal the flue and the boot device. To prevent this phenomenon in these conditions amplify (increase) the power of the torch lance 20 and the resulting foam is thrown into the chamber 6 and is precipitated oxidation of exhaust gases, which in turn allows 3-4 times reduce the time to rectify the dangerous conditions of the furnace.

When heating of the lining of the lower part of the walls of the furnace lining material undergoes linear movement relative to the adjacent deuteromony or cooled caisson wall. However, the proposed construction of the furnace of linear thermal elongation lined part of the walls of the shaft is compensated for by the gap 21 that does not "twisted" or destruction lined the walls inside the mine. It is highly desirable that the gap 21 was filled with granulated slag. Some of the granules when heated walls of the furnace will melt and seal the gaps between the end face(s) partitions 5 and the walls of the shaft furnace. The size of the gap 21 is chosen by calculation for a given (valid) maximum temperature and characteristics of the lining materials. Because the ends of the partitions 5 should cover the gap 21 over the entire height futuramas part of the wall of the shaft, the base width of the partition wall 5 should be not less than (3÷5)·5, where In is the calculated width of the gap 21. If the width is and the gap is less than 3V, you can directly access the powerful heat flows to the slag granules and their complete destruction, which affects the deformation or compensating ability of the granules on the one hand, and on the other, if necessary (for example, when the smelting of titanium-magnesium materials), you will be unable to equip the partition 5 cooling elements. If the width of the gap to take more than 5V then it leads to a significant loss of usable area of the bottom, and will violate the uniform temperature distribution in cross sections of the partition walls 5. It is highly desirable that the walls were made with a slope of more than 45° towards the bottom, which provides a higher stability of the septum against horizontal shear forces and damping of pulsating vibrations of the melt in the melting chamber 6, and also reduces the possibility of overgrowth of slag top edge of the partition 5.

Thus, from the description of the application shows that the application of the furnace of the proposed design allows to increase the duration of continuous operation of the prototype when receiving a matte or ferro-Nickel in a single unit, as well as to reduce operating costs by reducing the likelihood of emergency shutdown of the furnace.

Vanyukov furnace for the smelting of materials containing non-ferrous and ferrous metals, including caisson is ahtu, a rectangular bottom and widening at the top, separated by a transverse partition into melting and recovery of the camera, interconnected through the window for flow of melt in the lower zone of the transverse partitions, tuyeres located at the periphery of the walls of the mine, the furnace hearth stepped or inclined, the siphon with holes for release of slag and metalloceramic phase, characterized in that it is provided below the level mentioned tuyeres 5-8 diameters of their mouth in the window for flow of melt lance for regulating the flow of melt through him, and his warm, rectangular wall melting and reducing furnace chambers made of lined and over the entire height the transverse partitions are associated through thermocompensation vertical clearance, closed on one side caisson part of the walls of the shaft and with the other end of the transverse partitions made high strong refractory.