The development and application situation of SCOPE 21 coke-making technology was introduced, through the comparison and analysis on development and application, the difference existing between the expected case and applied case of SCOPE 21 can be seen. The difference between SCOPE 21 commercial device and single oven test device showed that hot briquetting temperature was reduced from 350~400℃ to 165℃; the temperature of coal charged into oven was reduced from 350~400℃ to 250℃; coke cake temperature was increased from 750~850℃ to 1 000℃; the coking time was extended from 7.4h to 13h. As viewed from actual operation condition, there was a certain difference between practicable effect SCOPE 21 commercial device and expected effect of single oven test device.
The features and present research situation of solid desulfurizers of iron, zinc, manganese and activated carbon systems etc. are analyzed and summarized. Iron oxide belongs to atmospheric temperature desulfurizer and can be used independently or used together with atmospheric temperature hydroxide radical sulfur hydrolyzed catalyst, but its desulfurization accuracy is low. After compounding, its desulfurization accuracy is improved, but the temperature is raised. The desulfurizer of zinc system has a higher desulfuriza?鄄tion temperature, but its desulfurization accuracy is reliable, it is widely used in industry. The desulfurizer of manganese system has a superior performance under high temperature and a strong regeneration capability, but it has a small sulfur capacity at lower temperature and it is normally used for smoke desulfurization under high temperature. The desulfurizer of activated carbon system is more suitable for the removal of organic sulfur.
The high volatile non-caking coal was preheated at different atmosphere, different temperature and different time in the self-designed heat treatment device. The influence of heat treatment condition on oxygen containing functional group, coal molecular structure, vitrinite random reflectance as well as pyrolysis and caking tendency were studied. The result showed that the volatile matter of non-caking coal after heat treatment was removed by 21%~25%; the hydroxyl removal rate in oxygen containing functional group of coal sample can be up to 90% or more; the H/C change of treated sample was not big, O/C is lowered by 50%. The experiment showed the possibility that the coal blend components can be replaced by the preheated coal sample.
The study on co-carbonization of coal tar pitch and lean coal with different blending ratios was conducted. The study showed that interaction of co-carbonization of coal tar pitch and lean coal was the coaction of physical bond and chemical interaction, in which the bond state of coke interface was improved by physical bond, and coal tar pitch varied the carbonization behavior of lean coal through chemical interaction with the increase of the blending ratio of coal tar pitch, the caking property of coal blend was greatly improved, OTI value of coke was increased, while ISO value was reduced. Coal tar pitch reduced coke reactivity and increased coke strength after reaction by means of increasing coke optical anisotropy.
The influence of 3 different kinds of tail gas treatment modes on thermal reactivity and strength after reaction of coke was studied. The result showed when tail gas was burnt off, coke thermal reactivity was the highest, and the strength after reaction was the lowest, the burning of tail gas deduced with alcohol lamp was in the middle; when tail gas was bled, the thermal reactivity of coke was the lowest and the strength after reaction was the highest. Under the same tail gas treatment mode, when the cold end temperature of thermocouple was 66℃, the thermal reactivity of coke was higher than 36℃; the law of coke thermal strength after reaction of 36℃ and 66℃ of cold end temperature of thermocouple was tended to the same.
The working principle and moving features of the driving mechanism of stamping machine are analyzed by selecting the design method and topological plan of kinematic link structure. And on the basis of the driving mechanism of the existing stamping machine, the topological analysis of the new structure is done, a series of regenerative kinematic links are evolved and the regenerative kinematic links are converted into a new type stamping driving mechanism. The study shows that under the prerequisite of no change of other conditions, the useful work done by the stamping hammers of the new plan is increased by 133.2J in comparison with that done by the stamping hammers of the original plan.
The carbon balance method is adopted for the calculation of CDQ coke burning loss at present. The carbon balance method can determine the burning loss of CDQ coke during stable operation, but when the production statistic is carried out, it is not preferred. The carbon balance method for the calculation of CDQ coke burning loss and for CDQ steam generation rate statistic is described in the paper. The method does not need to do the carbon discharge measurement and can be used for statistic calculation at any time. It is simple and its accuracy can meet the requirement of production statistic, meanwhile the analysis and discussion on the causes of coke burning loss during the operation of CDQ system are carried out.
The wet oxidation desulfurization technology using RTS as catalyst and actual running effect were introduced. RTS catalyst is of high efficiency in desufurization. It can separate out inorganic sulfur as well as part of organic sulfur, and the obtained sulfur is big in size and uniform. The practice showed that the desulfurization process running and desuilfurization effect were stable, the content of H2S in the purified gas was 10~20mg/m3, which can meet the demand of desulfurization for high sulfur coal.
The process of producing 40 000 t/a benzene anhydride with o-xylene by means of Aspen software was simulated, and the simulation results were analyzed. Cis-butendioic anhydride, benzoic acid and phthalide in light fraction column T201 were removed on the column top, the overhead component: benezene anhydride 25.74%, cis-butendioic anhydride 39.11%, benzoic acid 25.37%, phthalide 9.78%. For product column T202 top, except that very small amount of benzoic acid and phthalide were contained, the rest was benzene anhydride, the column bottom was heavy component, which can meet the separation requirement. In actual production, benzene anhydride content in light fraction was about 50%, therefore the reflux ratio in production operation can be enlarged, which can optimize the operation.
The circulation flow liquid phase micro-extraction (CFME) and gas chromatography-hydrogen flame ion detector were combined for analysis of phenolic compound in waste water, the condition optimum were conducted on the factor of influencing CFME, CFME and the national standard were compared. The result showed that CFME method after optimization and the national standard have good linear relationship, CFME has the advantages over simple operation, low cost, rapid and accurate feature.
The needle coke formation basic principle, production method, market situation, domestic production and application present situation were introduced. The domestic production technical level was analyzed, and the suggestion for domestic construction project was put forward. It was considered that the macroeconomic control should be strengthened, the development should be greatly strengthened, the product quality should be improved in stead of increasing output in the blind way.
The coal blend and coke-making experiment was conducted on 5 kg test oven to study the influence of additive amount and grain size of waste activated carbon, the result showed that it was feasible that in coal blending and coke-making lean coal was replaced by a certain amount of waste activated carbon, when the blending amount and grain size of waste activated carbon were respectively controlled at 0.5%~2% and 0.5~1.0mm, there was no influence on cold strength and hot strength of coke. To replace lean coal for coke-making with waste activated carbon can reduce the cost of coal blend, and the issues of wasting resource and environmental pollution can be effectively solved.
In combination with the rating data for various kinds of CDQ boilers and constraint factor existed in selection process of CDQ boiler, the factors such as productivity of CDQ, project investment and enterprise present situation were compared and analyzed, which has provided a suggestion for selection of boiler type for CDQ project. At the same time, against high temperature and high pressure natural circulation CDQ thermal system and medium temperature and medium pressure combined circulation CDQ thermal system, the difference of energy-saving, boiler efficiency, steel consumption, system electric power consumption, power generation capacity as well as the difference between boiler start-up and running were compared and analyzed, every advantage and disadvantage of thermal systems of two parameters were understood furthermore.
By measuring coal bulk density, temperature rise rate and crucible coke nature when coal charge moisture were respectively 1%, 6% and 12%, the influence of coal charge moisture on their nature was obtained. Although there was no big influence on coal charge nature lower coal charge moisture by lowering coal charge moisture, the dynamic state of coal charge in the coking process in oven chamber has changed substantially, which can greatly increase coke oven productivity and improve coke quality. When coal charge moisture was 1%, coal charge bulk density, temperature rise rate and nature of crucible coke were much better than that of coal charge moisture of 6% and 12%.
Development of wear-resistant pre-fabricated block and its application on CDQ chamber
The development achievement of wear-resistant pre-fabricated block which has been used on CDQ chamber of Baosteel was introduced. The wear-resistant pre-fabricated block has the excellent performance of falling resistance, good thermal shock stability, high strength and wear resistance. The result of actual application at Baosteel showed that the conventional burnt mullite brick used at the same location of CDQ chamber was replaced by the wear-resistant pre-fabricated block, the wear rate of wear-resistant pre-fabricated block was reduced by 70% or more, the service life of refractory used at the cooling zone of CDQ chamber can be substantially increased, and the repair frequency and consumption of refractory can be reduced.
The system for measuring oxygen content in coke oven burnt flue gas
The system for measuring oxygen content in coke oven burnt flue gas was introduced, this system can respectively take the samples of burnt flue gas from sole flues of several regenerators, and oxygen content in burnt flue gas was measured with one ZrO oxyen analyzer. In auto mode, automatic measurement of oxygen content in several downflue regenerators can be completed in one reversing cycle; In manual mode, the single regenerator can be continuously measured. The system is characterized by higher measuring accuracy, stronger real time ability, lower cost for investment and less maintenance, which has provided a measuring basis for judging the combustion condition of individual combustion chambers of coke oven.
Pneumatic delivery and utilization of dust collected from coke-making production
The principle, flow, feature, running of pneumatic delivery of dust collected from coke-making production as well as dust collected from coke-making production which is used for blast furnace pulverized coal injection were introduced, the key technical issue was studied. The production practice showed that long distance non-pollution delivery was realized in pneumatic delivery mode, material can be taken and discharged in many points, the process was automatically controlled. Dust also can be mixed quantitatively with pulverized anthracite injected into blast furnace, part of anthracite can be replaced, so that comprehensive utilization of non secondary pollution of dust collected from de-dusting was realized.
Against the development tendency of CDQ boiler of new CDQ project toward high temperature and high pressure and natural circulation, in combination with the past engineering practice, in view of technical and economic aspects, the determination of CDQ boiler parameters, proposal selection and three kinds of circulation modes were deeply and rationally analyzed and compared. It is suggested that high temperature and high pressure boiler should be used in large-scale CDQ system.
The process, equipment and energy consumption of gas naphthalene removal were studied. The new process of coke oven gas naphthalene removal developed by Masteel was introduced, one step naphthalene removal of gas was completed in cross tube primary gas cooler, after gas purification there was no other naphthalene removal unit. The average resistance of primary gas cooler was below 1 000Pa, primary gas cooler was not cleaned with steam, gas purification equipment was never blocked by naphthalene, 12 000t standard coal can be saved annually, the energy-saving effect was obvious.
Modification of dephenolization process of tar plant of coking plant of Anyang Iron and Steel Co., Ltd
According to the conditions of low efficiency of dephenolization, standard exceeding phenol content in naphthalene, poor neutral oil removing and dewatering results from phenolate, environmental pollution by intermittent phenolate decomposition, easy blockage of continuous phenolate decomposition column, low yield of crude phenolate and so on, crude phenol yield is raised and operation environment is improved through the process and equipment modifications of enlarging the capacity of buffer tank, changing steam source for the stripping process, increasing the packing in the stripping column, replacing the packing in decomposition column, installing agitator in intermittent decomposer and heater in the intermittent scrubber and so on.
The study and development process of the needle coke produced from coal in China are described. The basic theory, industrial test and production conditions of the needle coke produced from coal in our country are discussed. A stress is placed on the introduction to the raw material pretreatment, green coke preparation by delayed coking and production process for the needle coke produced from coal by rotary kiln calcination. The quality of the needle coke produced from coal and its applications in our country at present are evaluated objectively.
Long flame coal with the grain size of less than 0.2mm, coke fine and coal tar were mixed together according to a certain proportion to prepare the binder for briquetted coal to produce metallurgical coke. 10% of No.1 coal slurry binder and 8% of No. 3 coal slurry binder were blended respectively to briquetted coal production, by which briquetted coal with higher cold strength can be obtained, the compressive strength was greater than 100N/off, the falling strength was greater than 90%, which can meet the strength requirement of briquetted coal for coke-making in the course of production, transport and charging.
Against heat transfer issue of CDQ system, one-dimensional heat transfer mode in CDQ chamber and math model of circulation gas combustion at the outlet of CDQ chamber were set up, and the discrete and simulation calculation was made on them. The result showed that the math model set up was correct, it can be used as system simulation optimum operation and control basis. By means of the calculated result of the model, the responding relationship among the system circulating air volume, air volume introduced and steam generation volume of boiler were found, which was used to conduct off-line guidance for optimum operation of CDQ system.
The small scale test, medium scale test and industrial experiment on the improvement of coke hot property result are done by adding passivating agent based on SiO2. The study result shows that coke quenching with direct spraying of 5‰ water solution of the passivating agent based on SiO2 has a good improvement function of CSR and has very small influence on the coke cold strength M40. The addition of the powder of passivating agent based on SiO2 into coal blend reduces the coke hot property greatly and plays a negative role. The addition of the water solution of the passivating agent after normal coke quenching has almost no improvement result.
Aiming at the many problems occurred during the production test run of PROven system, the Coking Plant of Masteel has done a series of optimizations of its design parameters during its actual application so as to make PROven system functions more perfect. The optimized PROven system has not only solved the gas escaping problem on site, but also shortened the automatic interlocking time of charging car and PROven system. This can avoid the misoperation of operator and increase the safety and reliability of production operation.
The pre-sulfuration of catalyst can improve the activity and stability of catalyst and prolong the service life of catalyst. The reaction principle of pre-sulfuration of catalyst for hydrorefining, the sulfuration technology used at present in industry and factors that affect sulfuration are described. The sulfuration methods for different kinds of catalysts are compared and the matters needing attention during operation are put forward.
Trace moisture was existed in pure benzene products produced from Benzol-refining unit of Litol process of Shanghai Baosteel Chemical Co., Ltd, which can influence the product quality. The dehydration experiment was conducted with ND adsorbent, the study of static isothermal adsorption, adsorptive kinetics of adsorbent, and dynamic adsorption of fixed bed on trace moisture was made. Experiment showed that the dehydration effect of ND adsorbent was better, the experimental result can offer a basis for commercial design.
The paper makes brief description of background, principle and outline of the standard on coke oven emission of air pollutants regulated by U.S. Environmental Protection Agency. It is suggested to use the technical philosophy contained in EPA’s standard，such as to promote controlling of emission sources by advanced technology, more severer limitation of emission being enforced with progress of technology and so on, as reference for improvement of coke oven environmental protection standard of our country.
The development status and present situation of CDQ technology in China was reviewed and analyzed; the economic effect which was produced from CDQ system built and under construction was predicted. The problem existed in the development of CDQ technology was found. CDQ technology in China has been reached to the international leading position, CDQ technology and equipment have been reached to domestic production, CDQ system also is developed to the seriation, macro-scale operations technology and optimization, and the important technology breakthrough has been realized, but at the same time the problems of defect, lack of the unified industrial coordination management, construction corollary and imperfect of competition system were existed.
The energy saving and discharge reduction technology between high-capacity coke oven and stamp-charging coke oven was analyzed. After the disposal mode of high pressure ammonia liquor injection in single collecting main and the combination of de-dusting charging car and stationary bag-house unit for 7m high coke oven was adopted, the gas discharged can meet the requirement of environmental protection. The PROven system is used for 7.63m high coke oven and in combination with the charging car, its effect is equivalent to high pressure ammonia liquor injection + stationary bag-house unit. If 6.25m stamp-charging coke oven adopts high pressure ammonia liquor injection device, double U shape emission transfer car, oven door sealing device and oven end emission suction device on pusher side, the emission escaped can be controlled to maximum extent.
The foreground and superiority for developing stamp-charging coke oven in the northeast area are analyzed in detail from the aspects of stamp-charging coke oven distribution, the resources features of the coal for coke-making and climatic conditions and so on in the area. Liaoning area has the priority of the full utilization features of coal resource for coke-making in northeast area and north China and location superiority and is more adaptable for developing stamp-charging coke oven, especially the large-scale stamp-charging coke oven. The coal with high volatile matter can be added in the coal for stamp-charging coke-making to generate large amount of gas to moderate the problem of short supply of gas in Liaoning area and this has an important significance.
The main composition and various control functions of the automatic control system of large-scale continuous vertical retort are described. Aiming at the problems of low equipment level, low efficiency of manual operation, high labor intensity, poor operation environment etc. of the existing vertical retorts, the WebField ECS-100 control system and AdvanTrol-Pro software package are used to realize the monitoring and control of the process and interlocking operation of the equipment. The operation of the system has made a favorable probing for the standardization of the automatic system design of large-scale vertical retort.
The compensation condition, compensation method, selection condition and precaution of temperature measurement on top of coke oven regenerator were described. When the temperature measurement on top of regenerator is required to be compensated, the compensation proposal of temperature measurement on top of regenerator is selected by compensation of lateral temperature and longitudinal temperature uniform factor. For oven number with better uniform factor of lateral temperature, hetero-side compensation method is selected, for others, homo-side compensation method is selected.
The burning process of gas in the vertical flue of coke oven belongs to the diffusion combustion, the diffusion combustion is beneficial to the vertical uniform heating of coke oven and to reduce energy consumption. The height of flame produced from diffusion combustion was calculated in the paper, the influence of blast furnace gas heating and coke oven gas heating and the influence of waste gas circulation on flame height were compared. At the same time the factor of influencing flame height was also analyzed and the problem of coke oven vertical heating was solved.
The development process of coal moisture control technology was introduced, the difference of three generations of coal moisture control technologies was compared, the change of coal handling process due to the addition of coal moisture control system was discussed, it provided a reference for design selection. Four implementation proposals, namely coal moisture control with hot oil, coal moisture control with steam, coal moisture control with pneumatic classification were analyzed and compared, the issues to be cared in engineering application were given.
An introduction is given to the application of LonWorks field bus in the monitoring system for coke delivery belt conveyor. LonWorks field bus is not only arranged into bus structure, but also can adopt free topological structure. It is especially suitable for the fork belt conveyor system. LonWorks field bus is characterized by long distance control, flexible control structure and configuration, high transmission reliability of bus network, high ratio of performance and price and stable and reliable network performance.
Soda addition amount for ammonia stripping and optimization of soda feed location
On the basis of the production indexes of the ammonia stripping system in phase III project in Baosteel, the process simulation and study are carried out. The simulated result tallies with the production indexes and are reliable. The soda adding amount, soda adding location and steam consumption are optimized. It is put forward that when production is expanded in phase III project, the amount of soda addition is 350kg/h, the location for feeding soda is the nineteenth column tray and steam flow rate is 10 300kg/h.
Gas phase chromatography measurement method for phenols product composition
The Gas phase chromatography measurement method for phenols product composition is established. Phenols products are analyzed with 4 kinds of capillary chromatographic columns and the measuring conditions are optimized. The degree of separation for all components can reach 1.3, the accuracy and degree of precision are superior to GB/T 2601—1981, GB/T 2604—1981 and JIS standards and close to ASTM standard. The method is applicable to analyze the compositions of all coking phenols products.
Through the analysis on the composition of coking xylene, it is found that ethyl benzene and styrene is the main harmful impurity of xylene discoloration. The test result showed: the amount of acid addition should be controlled is 4.5%~5.0%, the optimum washing temperature is 45~50℃, and acid washing time is controlled at 7 minutes or longer. The measures of adding anti-oxidant into product, conducting secondary treatment and water washing can be taken for stabilization of product quality of xylene.
Study on factors affecting different levels of coke strength
The factors that affect the different levels of coke strength of seven kinds of coke produced fromseven single coals and one kind of coke from blended coal are studied. In the microstructure features of coke, the factors that have greater affect are the average wall thickness B of coke and optical heterosexual index H1. Microstrength is affected directly by the composition of optical organization of coke pore wall; the structural strength is influenced more greatly by porosity P and B, M40 and M10 depend mainly on B and H1, except that CSR is influenced by pore wall thickness and optical organization of pore wall, it has a close correlation with the composition of ash. The greater influences on petrology and coal quality index parameter are Rmax, S, ∑I and G.
The principle, main desulphurization process and actual application of the desulphurization by ammonia are described. Practice shows that the desulphurization by ammonia for large capacity boilers is characterized by high efficiency, less investment and less electric power consumption, and sulfuric acid or ammonium sulfate can be produced. Even if the temperature of flue gas is not reduced and it is sent directly into desulphurization tower, the higher desulphurization efficiency can be obtained. Through the comparison of many kinds of processes, a reference is provided for the selection of flue gas desulphurization technology for coal firing.
The coal blend for stamping coke oven is pre-treated in the fluidized bed equipment with coke oven flue waste gas as heat source and power source. Production application shows that the functions of coal blend moisture control and classification of fluidized bed type coal moisture control technology are obvious, after moisture control the moisture of coal blend is lowered by 2.2%, 1 474×104m3 return gas consumption is reduced, 8 750t of CO2 discharge and treatment of 20 000t of coking waste water are reduced, the production capacity of coke oven is raised by 5% and dust content in discharged waste gas is less than 50mg/m3.
Analysis is carried out for problem of the higher temperature generated in the production space inside the top of 7.63m coke oven designed by UHDE in Germany and the method for the effective temperature reduction in the top inside the coke oven is narrated. The temperature in the top inside the coke oven is reduced from 950℃ to about 870℃ through adjustments of gas orifice plate and spray nozzle plate for regenerator, the gas consumption is reduced by over 15% in comparison with the earlier period of the commissioning and problem of graphite grown on the top inside the coke oven is solved.
The process of producing direct-reduced iron（DRI） with coke oven gas was introduced. The production of DRI with gas-based vertical furnace was characterized by large production capacity, low production cost, flexible and convenient production operation and friendly-environment, therefore HYL-ZR rectifying process was selected first. From the viewpoint of circulation economy, to produce DRI with large volume of coke oven gas produced in iron and steel long flow production process instead of natural gas can form a new metallurgical process of iron and steel co-existed in long flow and short flow featured in our country, which was the transit selection of actual condition of iron and steel industry development in our country.
The determination proposal and working principle for coal charge moisture for coke oven are described and the calculating model for actual coal charge moisture is given. The practical application shows that the result of coal charge moisture gained through the treatment with the model is accurate and can meet the requirement of process. The coal charge moisture control module provides reliable data for the optimized control system for coke oven heating.
The experimental research and industrial practice on deep treatment of coking effluent with microwave technology was introduced in the paper. The test showed: the comprehensive effect of treatment of start microwave flow is better than stop microwave flow, there exists non-thermal effect in deep treatment of coking effluent process of microwave technology with microwave oven, namely existence of two functions (instantaneous and continuous functionsp）, the quality index of effluent from system is better than first class standard given in GB 8978—1996, the quality of coking effluent after treatment meets the quality requirement of return water. The microwave technology for treatment of waste water is the effective way of reducing fresh water consumption per ton of coke.
Determination of trace sulfolane and thiophene in benzene by gas chromatography flame photometry
The method for the determination of trace sulfolane and thiophene in benzene by gas chromatography flame photometry is established. The chromatography conditions are optimized and the external standard method is adopted for quantitative method. The recovery rates of the method after adding titer range from 114% to 136%. Relative standard deviation is not greater than 7%. The determination of sulfolane and thiophene in benzene sample is characterized by high sensitivity, good reproducibility, high reliability and so on.
WSA wet acid making process is characterized by simple flow sheet, low operation cost, convenient operation and good environmental protection result and so on. The process has a very good adaptability for increasingly strict environmental laws and regulations. A general description is given to the process flow sheet and features of WSA acid making process of Haldor Topsoe in Denmark. Emphases are laid on the description of the relevant operation and control requirements needing attention in the production application. Meanwhile analysis and discussion are carried out in combination with the problems occurring in the commissioning and production of the acid making plant of Shao-steel Coking Plant.
ISSN 1001-3709 CN 21-1164/TQ Sponsor:ACRE Coking & Refractory Engineering Consulting Corporation,MCC Postal Code:8-28
