The vertical aluminum alloy quenching furnace is a cycle-type resistance furnace, which is mainly used for the heating of quenched aluminum alloy parts. The vertical aluminum alloy quenching furnace has the advantages of uniform furnace temperature, rapid temperature rise, short water inlet time, and low energy consumption. The temperature control system of the vertical aluminum alloy quenching furnace adopts PID zero-triggered thyristor, and the structure of the electric furnace consists of bottom bracket, heating furnace body, heating element, hot air circulation system, mobile quenching tank truck, basket lifting mechanism, control system, etc. Partly composed. Brief introduction of vertical aluminum alloy quenching furnace: The vertical aluminum alloy quenching furnace consists of a heating furnace cover and a mobile chassis. The square (or round) furnace hood is equipped with a crane, and the basket can be hoisted to the furnace through chains and hooks. The furnace hood is supported by a profiled steel and the bottom of the oven door is operated pneumatically (or electrically). The base frame below the furnace hood can be moved along the track and positioned. The chassis carries the quenched water tank and basket. Vertical aluminum alloy quenching furnace features: (1) Temperature uniformity of vertical aluminum alloy quenching furnace The temperature uniformity achieved by the user is guaranteed by the associative design of the circulation fan, wind deflector plate, furnace structure, electric power distribution, arrangement of electric heating elements, control method and process, and door structure. (2) Vertical aluminum alloy quenching furnace with advanced mechanical system The advanced nature of the system is ensured by the design, component selection and quality, and processing and manufacturing quality. The mechanical system runs smoothly and reliably, and the equipment is in a state of low noise and low vibration. (3)Vertical aluminum alloy quenching furnace has perfect control system Reflected in 100 - 650 °C can achieve accurate temperature control, the system is stable and reliable, easy to operate, to avoid human error operation, complete functions and so on. (4) Quenching transfer time is rapid and adjustable Bottom-moving furnace door, rapid lifting mechanism, and advanced mechanical system make the quenching transfer fast and reliable. The time can be based on the user's process requirements, quenching speed ≤15S. (5) The quenching tank adopts a mobile trolley, or adopts the form of a pit, so that the workpiece can be processed conveniently and quickly.

1 Introduction Electric arc furnaces are widely used in the smelting industry. It is powered by a three-phase alternating current of a special transformer. The three-phase alternating current directly heats the metal in the furnace through three electrodes that move up and down. In the smelting process, the electrical load of the three-phase AC arc furnace is unstable and asymmetrical. Especially in the melting period, due to unstable arc combustion, arcing, short circuit and block movement often occur, resulting in serious load failure. Symmetry; when the electric furnace is running, the improper adjustment of the electrode regulator or other artificial causes will cause the three-phase current of the electric arc furnace to be asymmetrical. Therefore, the electric arc furnace is a nonlinear time-varying system with very serious random disturbance, and its three-phase current balance. And the stability of the temperature is difficult to control. Although the traditional control method is robust to the disturbance of system parameters, traditional control and single intelligent control are difficult to achieve good control effects due to the nonlinearity of the arc furnace control object and the time variation of the model parameters. To this end, we have developed a hierarchical control system for intelligent high-power electric arc furnaces, which has achieved good results in the practical application of lead-zinc smelting in Guangdong Province. High-power arc furnace temperature and electrode current balance hierarchical intelligent control integrated control system is mainly divided into organization level (fuzzy expert control system in the figure), coordination level (composed of electrode current integration optimization and three-phase current balance) and execution level ( The electrode control device performs hierarchical intelligent control control. The hierarchical intelligent control control system covers the whole production process of the lead-zinc smelting electric heating front bed. The relationship between them is as follows: U is the input signal in the figure, U={u Represents the slag type selected signal, u represents the electrode position feedback signal represents the current feedback signal, f is the online feedback signal from the execution stage to the coordination stage (furnace temperature feedback signal), and f is the offline feedback signal from the coordination level to the organization level. The organization level produces current signals, temperature control signals and corresponding operational indications that meet the requirements of the production process coordination level, and further for the coordination level of the electrode three-phase current balance integrated power system and its automation. 1 This article was received on November 25, 2002. The control provides optimized command current information; the coordination stage accepts the command current and provides the switch control signal to the execution stage according to the feedback information of the three-phase current; the execution stage accepts the switch control signal of the coordination stage, and the three motors respectively drag The three-phase electrodes of the electric arc furnace change their relative positions in the slag to adjust the electrode current, so that the three-phase current is balanced and consistently directed toward the command current, thereby forming a furnace temperature that meets the requirements of the production process. 3 Hierarchical Intelligent Control System Implementation The implementation of the system is accomplished by three levels of independent and coordinated. 3.1 Organization-level implementation First, obtain prior knowledge from a large amount of previous production information, complete the initial setting of the fuzzy expert system, as the loading information of the system reset at the beginning of each phase: 1) establish the slag type, furnace temperature and maintain the temperature The relationship between the current values ​​required for constant, the principle of reasoning is that the current increases with the increase of the furnace temperature and the slag type variation. According to the seven grades of the slag type, the furnace temperature ranges from 1000 to 1350 ° C, and the corresponding current range 1800 ~ 4200A; 2) Establish a relationship between the slag type and the target value of the optimum furnace temperature for separation of lead and slag, and the relationship between the slag type and the optimal target value of the slag retention. 3) Establish a table of relationship between electrode position, current and slag surface. The electrode position L slag height H can be obtained by the expression H=L kI; the implementation of current organization and temperature organization of the fuzzy expert system is described below. The current and electrode position signals continuously measured by the system during the entire EAF smelting production process, that is, the slag surface height is monitored indirectly. When the slag surface height increases rapidly, it means that the electric arc furnace slag control system enters the temperature control phase, and the optimum furnace temperature value corresponding to the set slag separation corresponding to the set slag type is taken out from the initialization table, and the temperature corresponding to the temperature Current values ​​and use them as target values ​​for temperature organization and current organization. The current organization is derived by the fuzzy expert control system. The expert system gives a reasonable current target value for the current organization, and then the two-dimensional fuzzy rule infers the offset between the current organization and the target current value. The difference between the actual furnace temperature and the furnace temperature target value ET, the furnace temperature change trend and the control amount current organization offset E is defined as follows: and the fuzzy set of E is: the fuzzy control rule can be blurred with the following 35 Conditional statements to describe. The output control quantity of the fuzzy inference, that is, the current deviation value E, is added to the current target value, and the sum is the required current organization signal. The temperature organization must meet the constraints of the process requirements. At the same time, as the input of the temperature-current model identified by the artificial neural network, in order to avoid the excessive output of the neural network due to input mutation, the temperature organization must be constrained to define the temperature organization T. It is expressed by the following formula: T is the furnace temperature at the time of slag introduction; it is the error value of the target furnace temperature T and T; t is counted from zero at the start of the slag temperature adjustment; it is the temperature organization change rate controlled by the expert system, The adjustment principle of t is to decrease when the temperature difference is large and the current is large; the above formula not only ensures that the temperature organization moves toward the target temperature direction, but also automatically adjusts the rate of change of the temperature organization according to the current magnitude. When the slag surface drops rapidly, it means that the electric arc furnace slag discharge control system enters the heat preservation control stage, and the optimal furnace temperature value corresponding to the set slag type and the current value corresponding to the temperature are taken out from the initialization table, and They serve as new target values ​​for temperature organization and current organization. For the same reason, the fuzzy expert system completes the control of current organization and temperature organization at this stage, and thus achieves control of a complete production organization. 3.2 Coordination level implementation This level is mainly to complete the current optimization. The current optimization decision system mainly adopts the following measures: 1) The decision-making system shields the current-assisted organization output by the artificial neural network at the time of slag or slag discharge, and unblocks when the current-assisted organization enters the power supply capability of the transformer. 2) Other smelting period optimization decision system weights current organization and current assisted organization according to the following formula: command current 3) constant temperature lead slag separation stage After the timer expires, the process requires the system to stop supplying power, so as to reduce lead boiling and improve separation effect. The decision system simultaneously shields current assisted tissue and current organization. 4) Once the furnace temperature drops to the set critical temperature during the power outage period, the optimization decision system first turns on the output of the current organization and determines whether the current assisted tissue is shielded. At the same time, current optimization is realized by expert fuzzy decoupling intelligent control and current expert decoupling control. Expert fuzzy decoupling intelligent control is a summary of the skilled workers' operational experience. It uses a large amount of qualitative prior knowledge to establish fuzzy, inferential, logical rule bases and reasoning methods, which are realized under the conditions of integrated process and on-site environment. The weakening coupling of the three-phase electrode current, and fuzzy control of the expert optimization result by the fuzzy controller, the adjustment time of the three motors is obtained, which determines the position change of the three electrodes; the system control performance in turn affects the expert controller The expert decoupling rules are optimized, and the quantization factors of the fuzzy controller are reasonably corrected. The input of the expert fuzzy decoupling regulator is the three-phase current balance given value, and the output is the adjustment amount of the three electrode lifts. The three-phase current balance control is realized by adjusting the three electrodes. The structure of the expert fuzzy decoupling current regulator is shown in Figure 2. The expert fuzzy decoupling control variable set is as follows: A phase current deviation amount Eia: B phase current deviation amount Eib: C phase current deviation amount Eic: A phase current deviation amount change rate $Eia: B phase current deviation amount change rate $Eib: C-phase current deviation rate change rate $Eic: No. 1 motor adjustment amount U1: No. 2 motor adjustment amount U2: No. 3 motor adjustment amount U3: Phase current deviation and deviation change rate; Ke, Kc are fuzzy controller systems The error and the quantization factor of the error rate of change; v1, v2, and v3 are respectively the motor adjustment time after quantization; three motor motion states; the motor regulation state -1 represents inversion, 0 represents stop, and 1 represents forward transmission. The current expert decoupling control divides the three-phase current deviation into five current deviation sets NM, NS, 0, PS, PM according to the actual deviation eia, eib, eic of the three-phase current, according to expert experience, can be summarized The three-phase current and the positional relationship of the three electrodes can weaken the coupling relationship of the three-phase current. The following rules can be summarized: the coupling between the three-phase currents is weakened by the expert decoupling rule, and the phases are respectively A, B, and C. The current is controlled by the fuzzy controller to achieve current balance and optimization, so that the adjustment time of the three motors is obtained separately. 3.3 Execution Level Control The main goal of the implementation level is to control the electrode position based on the optimized current output from the coordination stage, so that the furnace temperature is optimally controlled, specifically by entropy theory. To this end, the design problem of the control system is represented by probability, and a distribution function indicating the optimal solution uncertainty within the allowable control space is specified. When the distribution satisfies Jayne's maximum entropy criterion, the performance criteria for the control problem are related to the entropy of choosing a certain control. An optimal control solution is obtained by deriving the minimum value of the entropy of the average performance of the system. To get the best control of the furnace temperature, the average value of the system's Lagrangian function L(x, u, t) takes the following form: indicates the system state space, u indicates the input control amount (current), and t indicates the control time. L>0, subject to the differential constraints determined by the following basic processes: M is a cluster within 8. When u, the design uncertainty density is selected in the allowable control space to satisfy the Jayne maximum entropy principle, and the relevant entropy is as follows: where: S represents entropy and T represents furnace temperature. The optimal control then satisfies the following equation: then the problem becomes the minimum uncertainty in the selection of the optimal control within the allowable control space 8. Covered by the density function to reach the maximum. As long as the following formula is solved, the calculation result can be substituted into the formula, and the most effective control of the furnace temperature and the electrode position can be obtained. 4 Conclusion After the successful development of the device, the laboratory performance simulation test was carried out and put into use in the first and second systems of Shaoguan Smelter in Guangdong. The results show that the system is accurate, the control is fast and sensitive, and all functions can operate normally. In various harsh environments, the device operates well and has high reliability. It can ensure the smooth adjustment of the electrode, meet the requirements of the arc furnace temperature and the balance of the three-phase current, improve the labor intensity, reduce the power consumption, and improve the quality, output and management level of the lead-zinc smelting of the electric arc furnace.

1 reverberatory furnace. Reverberatory furnaces are commonly used equipment for smelting non-ferrous metals, and their structure is similar to that used in aluminum alloys. The heat source of the reverberatory furnace is nothing more than solid fuel helium and A), fluid fuel helium, and gas and electric heat. Fluid fuels are often used in the smelting of magnesium alloys. At present, China's main gas is natural gas or natural gas. The reverberatory furnace for smelting magnesium alloys is classified into a smelting furnace and a stationary furnace according to its use. The top of the reverberatory furnace is arc-shaped, and the heat is reflected from the top of the furnace and the wall of the furnace to the charge. Therefore, the heating of the charge is transmitted from top to bottom in a conductive and radiative manner, while allowing the flame and exhaust gas to slowly flow through the liquid surface. Keep the charge directly in contact with the heat flow. The reverberatory furnace burns faster and is suitable for large-scale production, but its thermal efficiency is low. The bottom of the reverberatory furnace is generally made of masonite and magnesia. Recently, cast iron has been used as a hearth instead of a refractory material containing SiO: because SiO: easily reacts with MgC12 in the metal and flux, causing lining loss and increasing the Si content in the alloy. 7 site vortex furnace. In the smelting of magnesium alloys, Kodak vortex furnaces are also widely used. Because the burning of the site vortex furnace is much lower than that of the reverberatory furnace, the working environment is better than that of the reverberatory furnace. Citrus A zP can be divided into resistance site JA P and gas mandarin vortex furnace according to its heating method. The structure of the resistor is shown in Figure 12-2. The resistive material is mounted on the wall of the furnace around the address vortex, and the resistive material is either filamentous or ribbon-like. Gasoline vortex furnace fuel is mainly furnace gas. The gas is sprayed into the furnace through the nozzle and sprayed along the direction of the tangent to ensure proper combustion position. Otherwise, the nozzle is sprayed directly on the wall of the site A, which may cause local overheating of the metal and even burn the mango cord. 3 No core frequency induction furnace. In the melting of magnesium alloys, iron-free industrial frequency induction furnaces have begun to use. Induction furnaces for the smelting of magnesium alloys cannot be of the fused channel type, because the refractory flux and slag deposition bottom of the furnace make the fused channels blocked. The citrus vortex used in the induction furnace can be welded with a 10-25mm thick steel plate or can be directly cast into a thick walled site with a wall thickness of 4060mm. Because the cast citrus vortex is easy to produce defects and has a large volume, it is generally used to weld the citrus pods. The coreless industrial frequency induction furnace is composed of a furnace frame, a furnace body, a sealed furnace cover, a ventilation system, a hydraulic system, a cooling system, an electromagnetic transmission, or a low-pressure injection system. The Citrus group consisting of multiple induction furnaces not only has high production capacity, but also because the charge and flame are not in direct contact with each other in the melting process, the amount of flux can be reduced, the working conditions can be improved, and the metal quality can be improved. With this smelting equipment, reliable purification measures are taken, and sealed injections are used during casting to obtain better quality ingots.

1 Overview The use of wet and pyrometallurgical methods to recover DC EAF. DC EAF has many research results. The pyrometallurgical process requires a reducing agent and is heated to a high temperature to produce crude zinc oxide having a low industrial value; while a hydrometallurgical process can produce high-purity metallic zinc and zinc oxide, but cannot completely leach zinc from zinc ferrite. The hot acid leaching method is very practical for treating zinc ferrite particles in DC EAF. For example, the sulfuric acid is cheap, and it is an effective reagent for leaching zinc in zinc ferrite at low temperature. The disadvantage is that when leaching under normal pressure, the jarosite can be produced at a pH of <2, and the toxic element PEAF cannot be leached. A few percent of the chloride must be removed prior to electrolysis to avoid attacking the anode material used in the sulfuric acid leaching system. Hydrochloric acid has also been found to be a very effective leaching agent for leaching zinc ferrite from DC EAF soot. The zinc yield is high and does not produce jarosite. When 90~1002 is used, 0.5~1mol/L HCl can be used to extract about 90% of total Zn, and about 80% of total Fe is dissolved. In the recycling process, the leaching and electrowinning steps must meet the requirements of 3 points: 1 All reagents should be recycled at a high rate and economically reused; 2 The product should be valuable, and the harmful residues should be as small as possible to save processing costs; The system should be safe, easy to operate, and not occupy a large space. The main advantage expected by the HCl leaching method is that the activity coefficient of HCl in an aqueous solution of 10.5~5mol/L does not decrease sharply with the increase of acid concentration and is different from H-SO%. 2 Chloride contained in soot Conducive to the leaching process; 3 no need to wash the soot for the removal of chloride; 4 soluble chloride can remove the toxic elements Pb and Cd from the soot; 5 can avoid the formation of jarosite; 6 in the chloride system by filtration Separating the solid to liquid ratio is easier in the sulfuric acid system; 7 the hydrochloric acid containing chloride solution has a higher conductivity than the sulfuric acid containing sulfate solution, which can lower the cell voltage. One of the problems with HCl leaching-electrowinning is the production of Cl- instead of HCl during electrowinning. When recovering nickel, the possibility of directly regenerating HCl with a membrane electrolyzer was investigated and it was found that when a single -18-cation exchange was used In the membrane electrolyzer, the decrease in the pH of the catholyte results in a low cathode current benefit and a poor quality of the nickel deposit. When a double membrane electrolyzer is used, the pH of the catholyte is kept stable, and the chlorin concentration of the anolyte is small. This electrodialysis process can recover metals and hydrochloric acid, but is less used in industrial wastewater treatment because of the higher investment and operating costs from the perspective of zinc recovery. This article focuses on the study of zinc and HCl recovery using a single membrane electrolyzer. 2 Research Example 2.1 Method Overview A two-step method was designed to completely extract zinc from soot by the countercurrent leaching method of soot and leaching agent. As shown, the soot is leached twice: for the first time, the zinc oxide is leached from the soot; the second time, the hot hydrochloric acid solution is reacted with the zinc ferrite residue from the low acid leaching vessel. The iron in the hot acid leaching residue was found to be hematite Fe-O) and goethite FeO*OH). The hot acid leaching filtrate has a lower pH and contains more ferric chloride, which is used to leach fresh soot. The solution is filled with air or oxygen to remove iron from the filtrate, treated with zinc oxide and metal zinc powder to remove other elements of the filtrate by low acid leaching, or to simultaneously remove organic matter with activated carbon. The clean liquid is transferred into an electric storage tank having an ion exchange membrane to produce HCl and zinc. Recovery of zinc from EAF soot by acid leaching and electrolysis 2.2 Test work 2.2.1 Characteristics of leaching leaching materials are shown in Table 1. Leaching was carried out in 700 ml of a reaction glass vessel equipped with a heat controller and a water-cooling device. The concentration of HCl is 0.5~2mol/L, the quantity is 500ml, and the soot is stirred between 25~902 to make it leaching. The pH of the acid leachate is 0.0 to 2. In order to eliminate iron, fresh soot is added together with a small amount of 29% H0 solution to adjust the pH to 4.0 to 5.0 to oxidize the ferrous iron. 100 g of soot was leached with a calculated amount of HC1. Further, zinc powder was added to the filtrate produced by the dilute acid leaching to precipitate Pb, Cu and Cd. The reaction was completed in 10 minutes, and the pure filtrate was suitable for electrolytic production of high-purity zinc. The residue precipitated after leaching and displacement was dissolved in hot aqua regia and analyzed by AAS. Table 1 chemical composition of EAF soot, wt% sample 1 sample average particle size:! m specific surface area: m2 / g * BET zinc ferrite: wt% Zn / soot in zinc ferrite > zinc ferrite is not completely separated from magnetite. Electrolysis was carried out in a rectangular electrolytic cell made of polycarbonate which was divided into two chambers by a cation exchange membrane. The exchange membrane was supported between two perforated 1 mm thick Teflon plates. The membrane area was 72 cm 2 and 18 cm 2 respectively. The electrode was 6 cm x 12 cm, but only 6 cm x 6 cm was directly exposed to the electrolyte, and the rest was covered with insulating varnish. The cathode is made of an industrial pure 99% aluminum plate polished with SiC paper, and the anode is a Pt titanium plate. The distance between the poles is 4.5 cm. The anode chamber is filled with 250 m11mo1/LH2S4, and the cathode chamber contains a 250 ml ZnCl2 solution. Air is blown in to inhibit the growth of dendrites from zinc deposits. The chloride concentration in the anolyte was determined using a chloride ion selective electrode. 1 ml of the sample solution was taken and diluted with distilled water to 100 ml. Before the chloride ion was measured with a chloride ion selective electrode, 2 ml of the ionic strength modifier 5mo1/LNaN03) was mixed with the dilute solution. The measured electrode potential is converted to a chloride concentration using standard calibration data. The chemical composition of the electrodeposited layer was determined by AAS and energy dispersive X-ray spectroscopy (EDS). The acidity of the catholyte was determined by titration with 0.5 mol1/L Na2C03 solution. 3 Test conclusion 3.1 When the zinc ferrite particles are dissolved in hydrochloric acid with a concentration of 1~2mol/L, the recovery of Zn is >90%. 3.2 In the solution of the acid molar ratio of 4.06.0, from the zinc ferrite Zinc is preferentially leached from the EAF soot. Iron is removed from the system with FeOOH and Fe23. 3.3 With dilute acid leaching, iron can be removed from the solution by means of oxidation. 3.4 EAF soot may contain organic complexes of metals, but can be removed with activated carbon without loss of Zn. The degree increases and decreases.