Energy-saving and Practice of Producing Ferronickel in Submerged Arc Furnace
Pig iron containing nickel is one of the important raw materials for stainless steel production. In recent years, it has been widely used and promoted in large and small stainless steel plants in China, which reduces costs in the production process.
As the product is suitable for the production of stainless steel, it is welcomed by all manufacturers.
With the increasing demand for stainless steel year by year, the output of stainless steel is also increasing, and the manufacturers are booming accordingly.
However, most of them are small and medium-sized submerged arc furnaces, with low equipment matching rates, uneven production processes and technology levels, high product consumption, low energy-saving efficiency, and even puzzled in the process of ferronickel submerged arc furnace reform and smelting.
This NEW variety has brought us some difficulties. But as long as we carefully analyze, bold innovation and brave practice, we can find out its smelting characteristics and solve some difficult problems.
We would like to share with you the experience we have gained in the production process and invite representatives to make valuable comments.
Pretreatment of Ferronickel
Most of the raw ore for smelting nickel-bearing pig iron in our country is from Indonesia, the Philippines, New Caledonia, and other places. Most of the raw ore belongs to powder ore, the attached water is about 30% and the crystalline water is about 10%.
Therefore, the ore can not be smelted until it has been sintered. Sintering is the first process in smelting, which not only affects the normal operation of smelting but also affects the technical and economic index of products. At the same time, high energy is also consumed in the process of sintering.
For example, gas, coke powder, coal, grain, and so on are all part of the higher cost of sintering, so we have been discussing how to sinter ore to save energy. Soil burning, machine burning, and kiln burning are various, but in practice, energy-saving and environmental protection should be the focus.
We consider that soil burning is inferior to machine burning and machine burning is inferior to kiln burning. Soil burning and machine burning have abundant production practice experience in our country, but soil burning resource is wasted greatly, the sintering rate is low, and no organization discharges. Soil burning will be eliminated and banned in a short time.
However, one-time investment and heat loss are high, so shaft kiln sintering and rotary kiln sintering are our best choices.
At present, the above two sintering methods are gradually practicing, popularized, and applied in the smelting process of submerged arc furnaces.
Although the successful experience of hot charge charging is still relatively small, everyone is now actively experimenting with it.
We have also seen many foreign factories, such as Indonesia, the Philippines, and New Caledonia rotary kiln sintering technology is relatively successful in energy-saving of ferronickel submerged arc furnace. If controlled well, the problem of sticking kiln can be solved, hot material can also be well applied and power consumption will be greatly reduced.
We should learn from some advanced experiences of energy-saving of ferronickel submerged arc furnace in the world, innovate boldly, practice courageously and make unremitting efforts. The use of rotary kiln sintering hot material into the furnace can not only save a lot of production costs but also make our products more competitive in the market.
At present, our company adopts shaft kiln sintering technology, which is characterized by simple equipment, low investment, low fuel consumption per unit of the finished product, low cost, large coefficient of utilization per unit volume, and small equipment area.
The disadvantage is that the temperature distribution in the kiln is not uniform, so it is easy to produce under-burning and over-burning. Now the industrial production technology of rotary kiln is being actively adopted.
It is undeniable that the rotary kiln should be the ideal sintering method to achieve energy savings in sintering.