Difference between electrode paste and closed paste
Difference between electrode paste and closed paste
Electrode paste is also known as self - baking electrode, is a kind of electrode semi-finished material made of electroforged coal, residual as aggregate, asphalt, tar and other binder.
In the process of use, the electrode paste needs to be injected into the ore furnace. When it is heated to about 400 degrees, the electrode paste is melted and sintered into a solid. When it is heated to 800 degrees, it combines with the original ore to generate huge heat and arc to complete the smelting of ore.
The so-called closed paste is only for the furnace type of the mine furnace.
Ore furnace is divided into closed, semi-closed and open.
These different types of furnace use electrode paste, because the furnace type is different, over time, the electrode paste applied in the closed type furnace is called closed electrode paste, referred to as closed paste;
Electrode paste applied to open or semi-closed furnace is called standard electrode paste or simply electrode paste.
The closed paste itself is a kind of electrode paste.
Of course, generally speaking, the quality of sealed electrode paste is one grade higher than that of ordinary electrode paste.
The resistance and ash should be better.
Application of Rongxing Carbon special closed electrode paste in nitrite furnace
1. Nickel-iron smelting technology in electric furnace
It is a good technical choice to produce nickel-iron in laterite ore furnace.
At present, it is considered that the better process route is that laterite ore - dehydration, block -- coke, flux -- electric furnace smelting -- to produce coarse nickel iron -- C, SI, S, P impurities, converter refining - nickel iron (granulation, pouring) or smelting stainless steel.
The process of directly obtaining stainless steel products from laterite ore has been realized in Inner Mongolia minto company.
According to the difference of process method, resource condition, product quality, etc., there are many kinds of nickel iron smelting technologies, such as direct reduction of rotary furnace, blast furnace, blast furnace and electric heating.
Among them electrothermal method can also be divided into electric carbon heat, electrothermal silicon method, from the product can be divided into a single nickel iron and nickel chromium composite or nickel chromium and cobalt composite alloy methods.
As far as we are concerned, we can only deal with the production technology of electric furnace nickel and iron, mainly talking about the content is the preparation and use of electric furnace nickel and iron electrode and other related technical issues.
1.1 Iron and nickel smelting furnace raw materials
Domestic nickel oxide mineral resources are very limited, at present domestic production of nickel iron with electric furnace laterite mineral resources from Indonesia, Philippines and other south Pacific island countries.
1.1.1 The laterite is dehydrated
The purchased laterite ore usually contains about 33% physical and crystalline water.
It is very uneconomical to use a large amount of water in electric furnace for nickel and iron smelting.
At present, almost all enterprises that have carried out nickel and iron smelting by electric furnace adopt the drying and dehydration technology of laterite ore.
1.1.2 Red earth ore prereduction
The most important treatment technique for laterite ore should be drying and prereduction.
Usually will dry laterite ore block and reductant coke or coal blending system, and then use rotary kiln for prereduction, nickel oxide, iron oxide reduction low prices for nickel and remnants of ferric oxide and raw materials (or melt), and in red-hot form into the furnace, (when conditions do not allow to offline after cooling load of electric furnace), or don't come out of cold choose metal particles is expected to add electric furnace, etc., to continuously improve the production of technical and economic indicators.
The deeper the technology of pre-reduction treatment, the better the quality, the lower the power consumption and the higher the efficiency of the nickel-iron produced by electric furnace smelting.
Because the large-scale use of laterite ore smelting nickel and iron production, in China is only three or four years, the technology is not mature, a variety of technical routes are different, the results of a large gap.
Its development trend is constantly improving.
1.2 Nickel-iron smelting in hot (electric) furnace
1.2.1 Development of output and capacity
The main equipment of using laterite ore to smelt nickel-iron is ore hot furnace.
Nickel content 11- 16% of the furnace nickel iron output, this year will reach 4 million tons of production scale.
Electric furnace equipment is being scaled up, from the previous conventional 6300KVA to 25,000-66000kva capacity of the thermal furnace.
At present, the majority of electric furnaces with 12500-33000kva capacity are used.
In view of the recent nickel iron production profit is better, about 1500-2000 yuan per ton of alloy, is promoting the construction of nickel iron electric furnace.
1.2.2 The process of smelting nickel and iron
Conditions for the production of nickel-iron from nickel oxide ore, used in thermal furnaces, are also improving, and fewer and fewer enterprises are using the crude process equipment of direct use of dry laterite ore to furnace.
Converting to pre-reduction, hot charge.
The nickel (and iron) charge loaded into the electric furnace grade, behavior, nickel and iron reduction depth, inclusion content, particle state, material temperature, etc., can affect the technical effect of electric furnace smelting, such as the furnace running well, how much output, power consumption, etc., will also affect the quality of nickel iron primary products or refined products.
Data show that using the sintered red clay ore, the smelting power consumption per ton of furnace charge is about 1000 KWH.
If the pre-return material is used, the smelting power consumption can be reduced to 500 KWH, and the output of inconel is doubled.
1.2.3 technological gap
In view of the great difference in the conditions of nickel-bearing charge used in domestic electric furnaces, the technical conditions and capacity of nickel-iron electric furnace equipment vary greatly.It is not difficult to understand that different nickel iron manufacturers may use different raw materials, production processes and smelting operations, their crude nickel products nickel content and other components may be different.The different components of laterite ore, the different processing route of raw materials and the capacity parameters of nickel-iron electric furnace all have different characteristics.At present, nickel and iron production spread unrestricted in more than 10 provinces and regions.This kind of chaotic situation is the current situation of China.A few years ago, a small blast furnace of one or two hundred cubic meters, to be phased out, was once used to smelt low-grade nickel iron.Not long ago, it declined rapidly because of its heavy pollution, high energy consumption and lack of advantages.
1.3 Historic contribution of nickel iron production
When China began its rapid development of stainless steel four or five years ago, it startled the western world and sent the price of nickel soaring to an astronomical 35-400, 000 yuan a tonne.Not long after the rise of laterite nickel and iron smelting, and quickly developed into an industrial scale, the stainless steel industry broke through the foreign nickel monopoly, blockade and containment.Three years ago, China became the world's largest producer and accounted for half of the world's output.
1.4. Nickel iron production of special electrode paste
Nickel iron electric furnace for the production of stainless steel nickel iron needs to make an important contribution.
It is the steady production of a large number of mine furnaces that has ensured the flow of millions of tons of nickel and iron into the stainless steel plant and the production of so many stainless steel products for the market.
The special closed electrode paste produced by gongyi rongxin carbon plays an important role in ensuring the long-term continuous and stable operation of the furnace.
Rongxing Group is China’s leading supplier dedicated to providing its customers with the quick quotes, superior quality products, competitive prices and fastest possible deliveries of carbon metallurgical materials and solutions. Founded in 1992 in east-central China, it develops closer customer relationships and taking on a larger role in the total supply and manufacturing chain. With over 20 years of expertise in carbon metallurgical industry, the company is committed to research & development, and providing a range of high quality, innovative, cost-effective carbon metallurgical products and solutions. Its main products are graphite electrode，electrode paste, calcined petroleum coke, and refractory. The range of product line covers carbon materials, graphite materials, refractory and water treatment materials. The annual production capacity of graphite electrode, electrode paste, calcined coke and refractory reaches 50,000 tons, 200,000 tons, 250,000 tons and 20,000 tons respectively. The company’s corporate headquarters is currently located in the Zhengzhou.