1. Product promotion for Shandong Chenyang Carbon Co., Ltd Research & Development of Low- consumption Carbon in Aluminum Industry Yu Yiru

2. Company profile Project R&D Project effectiveness Content Basic theory Experimental study Technology evaluation Industrial application test

3. Shandong Chenyang Carbon Co., Ltd established in 1987, is the largest wholly-owned subsidiary of Jining Carbon Group Co., Ltd and is one of the national high-tech enterprises in China. It has the R&D base for the production and technology of carbon anode used for aluminum electrolysis, with output of carbon anode 500,000tpy. It is the leading enterprise in the industry carbon used for aluminum electrolysis in China, the syndic units of China Nonferrous Metals Industry Association and CHINALCO; the member of The National Nonferrous Standardization Technical Committee; the vice-president unit of Carbon Branch; Postdoctoral innovation experimental base of Wuhan University of Science and Technology; Standard R&D demonstration base of carbon used for aluminum electrolysis; and it owns the state-certified carbon testing laboratory and provincial enterprise technology center. It has firstly passed the ISO9000 Quality Management System Certification, ISO14000 Environment Management System Certification and OHSAS18000 Occupational Safety and Health Management System Certification. The company with international reputation of the industry was awarded as the Shandong Technological Innovation Enterprise, National High-tech Enterprise and Shandong Star Enterprise of China’s Patent. Company profile

4. The company has always focused on the experiment & research of technology of carbon anode used for aluminum electrolysis; tracking and being responsible for drafting the national and industrial standards for a long term and conducting technical cooperation with scientific research institutions at home and abroad. By cooperating with universities and employing experts from home and abroad for technical guidance, with the bringing in, learning and re- innovation, the company studied the new techniques of carbon anode used for aluminum electrolysis, improved the performances of carbon anode continuously and then realized the carbon creating perfectly from carbon producing. The company creates values for customers by providing technology and services, and promotes the energy saving, consumption reduction, emission reduction, benefits increase effectively in electrolytic aluminum production, which improve the production technology of carbon anode, strengthen the improvement of technology of carbon used for aluminum electrolysis and lead to the continuous development of the whole industry. Company profile

5. The company has become the model of comprehensive utilization and circular economy. The scientific and technological achievements of waste gas utilization and cogeneration founded the beginning of the industry. For recent years, the company has achieved 10+ National Invention Patents, 20+ utility model patents and 30+ innovations; it has drafted 30+ standards and 100+ papers as well. The company has compiled a series of professional publication “Carbon anode production technology”, translated and publicly published many professional publications including ”The technology of carbon anode used for aluminum electrolysis”, which have promoted the carbon anode production technology progress in China. During the period of 13th Five Year Plan, the company will make greater contributions to the industry development and technology progress based on the principles of energy saving & environmental protection, circular economy and sustainable development, to speed up the pace of new carbon material series product R&D and industrialization. Company profile

7. Carbon anode, a material for making aluminum electrolysis, is hailed as the heart for electronic tank, playing an important role of breakover in the whole process. The carbon consumption is 334kg ／ t-A1 in theory while in practice it betweens 480— 530Kg/t-A1. The extra carbon consumption is for overconsumption or just residuals. The reason that the process consumed more carbon is related with the cell condition, temperature of electrolysis, the shape of carbon anode, the quality and residual hardness. More anode consumed, more electrolysis carbon discharged and it will undercut the electric current efficiency, increase fuel consumption and CO2 emission which are bound to push up the production cost. Project development

8. The project starts with influencing factors of carbon anode’s electrolysis consumption in the tank, effect of the raw material nature and production parameter setting. In addition, developing new technique, increasing pitch wetting and adhesiveness for the carbon anode grain, enhancing thermal shock resistance of carbon anode, improving roasting curve, decreasing reactivity of carbon anode and selective oxidation, cutting slags discharge, boosting anti-oxidation performance, lowering secondary reaction and extra consumption are all the goals the project intends to achieve. The project made huge contributions to the electrolytic aluminium industry concerning energy saving, consumption cut, emission reduction and efficiency improvement. Project overview

9. Shape of electric tank/ anode size Current efficiency Electrolyte temperature Carbon anode fluting Anode quality Reactivity of CO2 Air reactive Thermal conduction Basic theory

10. 1. Electrochemical consumption (electrolytic reaction) 2 Al 2 O 3 + 3 C ＝ 4 Al + 3 CO 2 2. Chemical consumption Chemical consumption which includes CO2 and air reactions is not only a major factor that causes anode overload, but also an evaluation indicator for carbon anode quality and performance. CO 2 reaction ： C ＋ CO 2 ＝ 2CO Air reaction ： C ＋ O 2 ＝ CO 2 3. Mechanical consumption The mechanical consumption is partly due to the selective oxidation of carbon anode. Because the carbon anode is anisotropic body, the reaction first occurs in active points, and isolates the weak activated charcoal granules, making them falling off into the electrolytic cell to form carbon residue. The poor thermal shock resistance of carbon anode is another cause. During electrolysis, carbon anode may fall off or broke as a result of the arris defect, chip off-falling, fragmentation or even fracture. Electrical consumption of carbon anode

11. In the electrolytic cell, the oxidation reaction mainly occurs on the top of the anode which is exposed to the air and the lateral surface where the temperature is 400~600 ℃. This reaction is not only associated with the quality of carbon anode, but also with the actual operation during electrolysis, for example, the anode will be oxidized if the cell temperature is too high, or the coverage of carbon anode isn’t good. And this kind of consumption accounts for about 5%~10% of the total consumption. The reaction is as follows: ≤713 ℃ C + O 2 CO 2 ＞ 713 ℃ 2C + O 2 2CO The chemical consumption of carbon anode: air reaction

12. In the process of electrolysis, the composition of primary anode gas is almost pure CO2, but the actual anode gas contains only 70% ~ 80% CO2, while the rest is CO, which is no doubt the product of secondary reaction or even higher level reaction. CO2, which is a primary reaction product, will precipitate on anode bottom palm, making carbon anode surrounded by CO2, and the following reaction is bound to occur: CO 2 + C 2CO This reaction is endothermic reaction, which occurs mainly on carbon anode where the temperature is over 900 ℃. With electrolytic process going on, carbon anode erosion which is caused by CO2 is becoming more and more serious, and the reaction occurs not only on the surface of the carbon anode, but also deep into the internal anode 5 ~ 10cm. This reaction does great harm to carbon anode, and makes up 2%-10% of the total anode consumption. The chemical consumption of carbon anode: CO2 reaction

13. Oxid ation resist ance of anod e is poor Oxidation slag off Increase carbon consumption of electrolysis Oxidation slag off Anode pressure drop rise, heating, promoting oxidation Decrease conductive area Increase electric current density Increase the contents of electrolyte carbon slag Resistance increases and voltage rise High energy consumption, heat cells, instable of cells condition Carbon slag accumulated and gathered at the bottom of anode Isolate alumina Cause sudden effect, high energy consumption and instable of cells condition Carbon slag accumulated and gathered Anode has lumps, short circuit of the two poles, voltage swing, partial overheat Reduce current efficiency and increase power consumption The impact of anode carbon slag to electrolysis production

14. Decrease bubble layer of anode bottom, reducing pressure drop of anode Enhance electrolyte movement in order to help alumina dissolve Decrease turbulent fluctuation of electrolyte causing by bubble and reduce the surface metal vibration of electrolytic cell in order to reduce the noise of electrolytic cell After carbon anode slotting  The resistance of the bubble may be reduced from 200-300mv to 10-100mV  Longitudinal slot is the center of material preparation for oblique electrolytic cell, thus electrolyte can blend batter and alumina can get better melting. Carbon anode slotting

15. Dense degree Mechanical strength Pore conditions Conductivity Heat-conducting property Heat-conducting property Cover material conditions Cover material conditions Electrolytic operation Electrolytic operation Chemical purity Chemical purity Chemical activity Chemical activity Chemical property of carbon anode Electrolytic cell environment Influence factors of carbon anode electrical consumption Thermal field Magnetic field Electrolyzing temperature Electrolyzing temperature Physical property of carbon anode

16. Based on experimental studies, production tooling control is improved; production process parameters are optimized; petroleum coke blending scheme is tested; production formula is studied; performance of asphalt wetting is promoted; baking curve is optimized; technologies like reducing carbon anode reactions are improved; performance of anodic anti-oxidation is enhanced; hardness of residual anode is improved to reduce the anode electrolytic consumption. Technical Assessment

18. Industrial tests show that the carbon anode with low consumptions developed by the company is active in resistance to air and CO2 erosions, contains less carbon residues, performs well in hardness of residual anode and regularity and can withstand high current density with low consumption rate for electrolysis. The extension of one day for such kind of carbon anode can reduce 0.35-0.4 replacement period for anode. One ton of aluminum can lower carbon consumption by 15kg in electrolytic process and CO2 emissions from electrolytic aluminum by about 55Kg/t-Al, which is in accordance with the requirements of low carbon industrial policies and environmental protections, promoting the development of carbon anode technology in aluminum production and electrolytic aluminum industry. Project results

19. 1. Low electrolytic consumption rate can prolong the life cycle by one day More than 90% residues are left after the interaction between carbon anode of low consumption with air and CO2 respectivity. Such carbon anode of low consumption performs excellently in resistance to air and CO2 erosions with high inoxidizability and the consumption rate is better than that of other common anodes. Based on the same consumptions, its life cycle can be prolonged by one day. (0.4—0.6 mm/d) 2. The hardness of residual anode is better with high regularity Low consumption carbon anode is powerful in resistance to air and CO2 erosions with no oxidation dregs, blocks and anode pieces and etc. It belongs to hard residual anode with well performance in shocking and washing and high regularity, which can withstand high power currents and is favorable for the electrolytic operations with high currents. 3. The carbon consumption is low in the electrolytic process with less carbon residues. Carbon anode of low consumption bears high inoxidizability and low chemical consumption and the life cycle can be prolonged by one day with carbon consumption reduced by 15kg in electrolytic process. In addition, it is also lower in selective oxidation with less carbon residues. Project results

20. 1. Lower carbon consumption, lower production cost Low consumption carbon anode could reduce 15kg carbon consumption for every ton of electrolytic aluminum, indicating direct economic benefit of 3,000tpy of carbon anode consumption reduction for a 200,000tpy electrolytic aluminum plant, which would certainly lower the production costs. 2. Less carbon slag, lower fluoride salt consumption Low consumption carbon anode features with a high anti-oxidization property, a low selective oxidization property and generates less carbon slag, which could not only reduce the fluoride salt lose in the carbon slag filtering process (according to test, carbon slag contains 60-70% of electrolyte) but also let out less pollutants. 3. Larger current density, more yields The hardness of anode scrap endows it with high resistance against erosion and corrosion, as well as good regularity, so that it could bear larger current density, which will strengthen the current and raise the output of electrolytic aluminum. Economic benefits

21. 1. Lower labour intensity Low consumption carbon anode requires 0.35-0.4 times fewer of anode replacement frequency, indicating a 3,000-piece reduction of anode replacement every year for a 200,000tpy electrolytic aluminum plant. Also, as it produces less carbon slag, the difficulty of carbon slag processing has also been weakened. 2. Less heat lose and less pollution gas discharge Low consumption carbon anode could effectively avoid the heat lose in anode replacement and the discharge of fluorides and dust, which could reduce the energy consumption and the air pollution of the process. 3. Less emission of Co 2 Low consumption carbon anode could reduce 15kg carbon consumption and 55kg of Co 2 gas emission for every ton of electrolytic aluminum, which will help reduce the Greenhouse Effect. C + O 2 = CO 2 44×15÷12=55 kg/tAl C + O 2 = CO 2 44×15÷12=55 kg/tAl Social benefits

22. Research prospect Taking the development of carbon industry as our own duty, base on the development requirement of electrolytic aluminum production, Chenyang will conduct deeper research and experiments, further develop the technology of low consumption carbon anode for electrolytic aluminum use, produce more “green” products of low carbon consumption, and make more contribution for the advance of aluminum use carbon production technology and the development of the aluminum industry.