Fuming Furnace Smelting Process And The End Of Judgment-based Intelligent Control System

The fuming furnace is an equipment of extracting the metals of lead, zinc, tin and rare metals by deoxidizing-volatilization from the mine slag of smelting process. There are several decades'times of smelting practice using the fuming furnace in our country. And it is also widely used for processing low quality and difficult to beneficiate of tin and zinc oxide concentrate mine in nowadays. However, the current control way is determining by the operator's experience of observation on the flames from the tertiary air orifice of furnace through their naked eye. The judgments are gained, including furnace conditions suiting for deoxidizing-volatilization, volatilization processing, mine volatilization approach to finish, the end point of volatilization, so as to accomplish the smelting process. The process of fuming furnace is complexity, the correlative complication is multitudinous, the condition of smelting fieldwork is rigorous, the detection technology is restricted in thus instance. So far the automatic control system is not realization in the smelting process of fuming furnace.The paper is proposed on the fuming furnace, research the actuality, the developments, and the last word of this domain. The working procedure and the pyrology principle of fuming furnace are also researched. The thesis aims at the object of lag-time, non-liner, chemism-complicated, interferential-complication, hard to modeling mathematical expression of fuming furnace combustion system, puts forward the control strategy of Fuzzy PID combination Experts System to realize the temperature control of combustion system. It ensures a better control precision and achieves a rapid heating and temperature stability, reaches the temperature requirements of operating period.But only determining the temperature parameter, the automatic control system of fuming furnace is unable to achieve. The smelting process is discontinuous; the raw material in each period is not the same; the physical parameters conditions are different. It is hard to formed a certain control mode. By collecting the experience of the excellent operators from the fuming furnace fieldwork, the blown smelting curves for mult-conditions as experts are formed. Design the integrated intelligent control system combines with experts blown smelting experience, image recognize of smelting process, information fusion based on mult-sensors of End Point Judgment of smelting process. Realizes the smelting process control of fuming furnace, and make it work in a better state, the parameters of volatilization of Zinc and proportion of Zinc in residue are also in a better state.To realize the integrated intelligent control of smelting process, it is necessary to realize the judgment of smelting end-point. There are distinct differences of characteristic parameters between the non-end point and end point by disposing the fume images with the RGB method, YUV method, gray histogram, binary bitmap theory and gray level co-occurrence matrix. It provides a new method and technological thought on the judgment of end point of smelting process.Base on the above research and the collection of the operator's experiment on the fume images of the tertiary air orifice, it is easy to find the commonalities and differences through the colors, transparence luminance and morphology characteristic parameters. The system uses a color digital video camera for flame image collection, according to the different levels of colors, transparence luminance and morphology, the images are divided into volatilization, gloomy eruption, weak volatilization, weak red, bright yellow and white thorn. Then extracting the characteristic parameters of flame picture on area, luminance, chrominance and histogram as the input of the neural network, to realize the classifying and recognizing of the flame pictures. Based on the mapping relationship between flame images of tertiary air orifice and status of the smelting stages, the method of automatically determine of end point is formed, developed a system of automatic judgment of the end point of fuming furnace smelting processing. Taking into account the smelting process of flame flickering and jumping, the method of in accordance with the process information relation to the judgment of end point, general considerations for 20 seconds of 10 images classification results, to determine the current smelting process in which stages, then output with the previous judgments and statistical, finally the results is acquisition for whether in volatilization, calefactive phase or the end point of smelting.There are once, twice or time after time smelting volatilization of fuming furnace, and every time the end volatilization picture is similar as the end point picture. To achieve the exact end point judgment of smelting processing, relying on single picture sensor information of single judgment is inadequate. Fuming furnace smelting process is complex, the dependents of those various on judgment of end point have non-linear relationship, should not set up precise mathematical relationship. After several times of field research, the fuming furnace's status identification have relationships with the number of cold material, smelting time, the volume of coal, furnace temperature and the characteristics of tertiary air orifice, so using multi-sensor data fusion approach to achieve the end smelting judgments. Using the fusion algorithm disposing the information of temperature, cold material, smelting time, the volume of coal which from the detection system, and the image recognizing system. Based on D-S evidence theory algorithm, integration the judgment of neural network, images recognize and template with parameters, the finally result of end point judgment of smelting process in fuming furnace is formed, also develops the software system of end point judgment of smelting process in fuming furnace.The integrated intelligent control system of smelting process and the judge of smelting end-point system described in the paper have been applied in HUIZE lead smelting factory of YUNNAN CHIHONG ZINC&GERMANIUM Co., ltd, and have achieved greater economic and social benefits.