A Big Change -- Yilong Refractory, renamed as Changxing Refractory

    

    A big change has taken place in August 18, 2014, Yilong Refractory is officially renamed as Changxing Refractory due to the largest investment from Changxing Refractory. And also, the full name changes from Luoyang Yilong Refractory Co., Ltd. to Xinmi Changxing Refractory Co., Ltd. In the meantime, Yilong Refractory, exchanges the place with Changxing Refractory, being one of the three subsidiary corporations. 
    The name has changed while what will remain unchanged are our product quality and service. Changxing Refractory will take the responsibility of Yilong Refractory to provide customers with excellent services. 
    Thanks for your longtime support and welcome to cooperate with Changxing Refractory. Changxing Refractory will not disappoint you.

How to Protect Refractories and Lengthen Service Life of Lalde

The MgO in slag is eroded usually by furnace lining while making steel. In the process of smelting, the slag and refractory materials will get touched; MgO concentration in slag should almost reach saturation. There is a close relationship between the content of saturated MgO and CaO/SiO2. For slag with low alkalinity (CaO/SiO2<2.0), the higher the proportion of FeO is, the lower proportion of saturated MgO. When FeO content is low and saturated MgO content is high, the slag will erode more refractories. While for slag with high alkalinity (CaO/SiO2 >2.0), the saturated MgO content will not be seriously affected by the FeO content, what’s more the slag will not erode much more refractories. Therefore, improve slag alkalinity can strongly protect refractories.

The service life of ladle is directly influenced by refining time, so it is important to improve steelmaking technology so that to shorten smelting time.

The service life of ladle will be reduced by 3-5 heats once shut down, so to achieve efficient production, the key is shortening smelting cycle. On the premise of using advanced technology to guarantee the best steel quality and the lowest total consumption, shorten the smelting cycle to the minimum, improve equipment and shorten shut down time.

How to Improve Free-opening Rate? -- Flow Guiding Sand

With the expansion of the production scale of the grade steel, the automatic free -opening rate of the ladle will affect the smoothly running of production and quality of the slab. The quality of the products have been improved by analyzing the influential factors and adopting appropriate counter-measures, such as using flow guiding sand which also named stuffing sand

or steel flow initiator.

Flow Guiding Sand is a kind of ladle slide nozzle filler which is successfully developed by Yilong Refractory in recent years, results show that ladle castable success rate of automatic free-opening rate can reach above 95 percent. There is no metallic inclusion in ingot surface, is a kind of ideal ladle slide nozzle filler. Steel flow initiator contains metal mixture whose weight is heavier and melting point is lower than molten steel. Before pouring we put it into the upper nozzle, using it to burn and cause the molten steel within the upper nozzle will not be solidified, to achieve the purpose of automatic pouring and avoid the problem of ingot inclusions. 

One research of Luoyang Research Institute of Refractory shows that the higher content of water in flow guiding sand, the lower compression strength of the sintered temperature product, the greater the apparent porosity, the smaller the bulk density, resulting the lower of ladle automatic opening and pouring rate.

A Brief Introduction of AOD Refractories

Now magnesia-chromite brick, magnesia-dolomite brick, dolomite brick are the main products used for AOD lining.

There are natural dolomite at good quality in Europe, there calcined dolomite brick to are used generally to construct AOD lining. And magnesia-dolomite brick added with zirconia is used for tuyere, calcined dolomite brick with magnesia is used for slag line. For steel-tapping spout, magnesia carbon materials and magnesia dolomo carbon brick are widely used.

The corrosion resistance ability of magnesia chrome brick is high for high alkaline slag with magnesia and low alkaline residue with chrome, it’s the best choice for furnace whose slag composite changes are big, and it is widely used in Japan and America. While because magnesia chrome brick is expensive and chrome can do damage to the environment, so such kind of refractory brick is used less and less in the recent years. Only a small amount of small converters which don’ t work continuously use magnesia chrome brick.

Compared with the past magnesia chrome brick, dolomite brick is cheaper, but its serving life is also shorter.

Nowadays because magnesia calcium brick has good high-temperature resistance, slagging resistance and thermal shock resistance, and also it can purify molten steel. So it is gradually used in jumbo furnace which works continuously, and a trend of taking place of other refractory bricks seems to happen.

Measures to solve refractory brick damage

After analyzing mechanism and causes of refractory brick damage, then we can take corresponding countermeasure and measure according to these reasons to reduce the damage, so as to achieve purpose of extending service life of refractory brick.    According to the explanation of our technical staff, we know the cause of refractory brick physical damage and chemical damage ash and kiln skin erosion thin, mechanical damage and the refractory brick masonry quality. That is to say to extend the service life of refractory bricks in burning zone, in addition to select suitable suppliers, shall be laid a good grasp of building quality, maintain the skin at the kiln during operation. The specific measures taken are as the following two aspects.

On the one hand, maintaining the quality of laying refractory brick.

1. Cement ratio and dilute the appropriate thick. Specific detection method is easy to spread the cement shop into the brick, and can not flow. Too thick is not easy to spread too thin, is easy to flow; two is in a brick on the fire clay, pressure on another brick slightly strong kneading, and then lift up the brick body, the brick below belt, that the proper proportion of cement.

2. The front of refractory brick to be close to the cylinder. Between the brick and the cylinder body cannot pad fireclay and other debris. In the pool of fireclay brick, in front stretcher rectangular to leave 1 to 2 cm position does not stand in the cement, upward pressure brick, end close 

to the cylinder pressure to the fireclay, knead move, make cement covered the face brick, a small amount of excess cement extruded from the bricks and the small end of the big two, brick end matter stick cylinder. Brick joints cannot be greater than 1.5mm. Check brick facet, row not up, wrapping phenomenon.

3. The top tight top bar. In half of the circumference of the masonry, with top carry to brick top tight, rotary kiln bricks on the other half of the week, when the top bar must be the top tight. Some cube material should be laid between brick and the top bar, to avoid damage of refractory brick. Method to check whether the roof top bar tension is, when the top bar with the rotation of the cylinder to check the cylinder top brick not flagging lock position, if the sagging phenomenon, in the kiln and kiln refractory during the relative displacement caused by mechanical damage to the refractory brick.

For the other aspect, click here for the next industry news.

On the other hand, hanging up and maintain kiln coating. We suggest taking the following measures. 

1. For kiln operation training and guidance. Before firing, give the workers a training about kiln operation. Clearly pointed out that in any case, hang up and maintain good kiln crust is mainly the responsibility of kiln. At the same time about operating method under different conditions to them, in the actual operation, according to the kiln to give operation guidance and comments in a timely manner, to carry out technical exchanges between operations, and constantly improve the technological level of operation.

2. Coal spraying pipe should be put in the proper position which tending to the lowr side is the best.

3. Improving technology level.

4. Proper proportioning solution: the quantity of liquid phase resistance is suitable in 22-24%. Too low is not easy to hang kiln skin, too much can narrow the range of sintering temperature, silicate minerals reduce, not conducive to the operation and improve the quality of clinker.

Damage situation and its causes of firebrick

With the industry firebrick using time longer, refractory bricks will be damaged, and the damage mechanism can be divided into physical damage, chemical damage and mechanical damage. Luoyang Yilong Refractory Co., Ltd. Produced various refractory products, has a professional technical staff, based on our years of experience summed up the causes of various damages, can be summarized as follows.

1. Physical damage

Physical damage mainly refers to the high-temperature damage to the refractory brick; the cause of the damage can be divided into follows:

The intrinsic quality of refractory brick: high temperature resistance of the refractory brick, which is refractory brick refractoriness, refractoriness under load.

A) The reason of the process: The kiln crust thickness and the firm degree. Refractory brick kiln firing without skin protection, its service life is certainly short. The kiln skin erosion thin can be divided into operational reasons, reasons and technical reasons ingredients.

B) Operational reasons: The refractory nozzle position, the flame shape and the manipulation. The fire nozzle position bias lining erosion, flame kiln skin, make the skin thin flame kiln corrosion; stocky, scour kiln skin, make skin corrosion damage of refractory brick kiln thin, unstable operation, make the kiln peel off frequently, damage of refractory brick kiln; temperature is too high, the damage of refractory brick kiln crust, damage.

C) Ingredients cause: Batching scheme unreasonable, such as the KH value is too high, the amount of liquid phase is too low, not easy to hang kiln skin, also can damage the refractory brick.

D) Process: Mainly kiln mouth before the knot ring, so that timely discharge of materials not in the kiln, the abrasion function make kiln crust thinning damage of refractory brick.

2. Chemical damage

Chemical damage mainly refers to the kiln feed in R2O; etch S fusible substances on the refractory brick and damage of firebrick. But if the kiln skin firm and compact, and to resist easy melt material erosion of refractory brick damage.

3. Mechanical damage

Mainly refers to the period in the kiln is mechanical damage of refractory brick, brick and kiln relative displacement generated irregular, damage caused by shear stress generated by the firebrick. Phenomenon of kiln is running after a period of time, twisted slit brick. Cause mechanical damage associated with refractory brick size error and quality of masonry.

Have a clear understanding of the causes of various damages, we can take measures so that the losses to the minimum, thus a lot of cost saving in our production.

Yilong calcium silicate products are successfully exported to Greece

This year, the International Trade Department of Luoyang Yilong Refractory Co., Ltd., in 

consolidation of the existing customer base abroad, and actively develop new international customers, make customers in the shortest period of time to become familiar with the product's features and benefits of Yilong, recently, for the first time five hundred high quality calcium silicate 

products successfully sold to the Greek market.

Calcium silicate products are used in industries including steel plants, cement clinker kiln, 

heat and power stations, foundries both ferrous and non-ferrous, cement producers, ceramics, 

coke plants, incinerators, renewable energy, chemical works, sugar refineries and petrochemical industry. Our products won a lot of trust both at home and abroad. 

March 2014, the Greek customers conducted a series of audits on the quality of calcium silicate and company qualification, our international trade excellent staff through communication with customer, professional and technical personnel to provide the physical and chemical indicators, finally make he got satisfaction, the current manufacturing operations department are also based on customer demand full producing.

Customers said that after the completion of this transaction, will maintain long-term cooperation with our company, and products will involve more refractories. The first Greek customer entered into collaboration with our company, firmed foundation in the international market, and good for our company to develop new international markets in the future provided valuable experience.

Notes About Fire Bricks Laying During Furnace Construction

1. Construct the furnace either by one kind of brick or by two kinds of brick, the required matching percentage of brick in theory may differ from the actual percentage affected by distortion of cylinder. So there is no need to use bricks totally as the theoretical required amount while constructing the furnace. It’s a key point to lay the big side of brick close to the cylinder when doing the construction, and the bricks should be laid straightly and there had better no gaps between each two bricks. Fill the gaps and distortion with mortar, the repair seam line should not be too hard in case of breaking of bricks.

2. Abandon the twisted bricks which are out of distortion standard, making sure that the bricks are tightly bonded and no looseness. While construct the furnace by bricklaying machine, the upper brick especially alkaline brick can not be given too much pressure, because alkaline brick’s strength at normal temperature is relatively lower. Avoid bricks broken by uneven compression, so that to avoid kiln body falling off while working.

3. While laying alkaline bricks, watering or grouting the brick upper surface is prohibited. The well up cement mortar should be cleaned before it hardens.

4. Construct the furnace strictly according to each brick matching method to avoid distortion of brick block and kiln body working out of balance, furthermore to avoid affecting working cycle.

5. During the construction, check carefully and immediately both annular flatness and axial flatness according to the datum line in every circle and section. Parallel vertical seam line with furnace axis, parallel annular seam lines with each other, and make the parallel annular seam line vertical with the furnace axis. If the furnace body distorts or the bricks are irregular, adjust the body by steel plate and the bricks by cement mortar. The steel plates should just fit with the bricks (the length and height of steel plate should be 5mm smaller than those of brick).

6. When finish semicircle construction of the furnace, firstly check the deviation of vertical seam line with datum line and annular seam line with datum line, then lay one tier or two tiers of bricks, set up the mandrel and turn the furnace by 900. Construct the left half furnace on the other side, set up another mandrel while finishing one section. Turn the furnace after the mortar hardens.

The Ways to Protect Refractories and Improve Service Life of Lalde

The MgO in slag is eroded usually by furnace lining while making steel. In the process of smelting, the slag and refractory materials will get touched; MgO concentration in slag should almost reach saturation. There is a close relationship between the content of saturated MgO and CaO/SiO2. For slag with low alkalinity (CaO/SiO2<2.0), the higher the proportion of FeO is, the lower proportion of saturated MgO. When FeO content is low and saturated MgO content is high, the slag will erode more refractories. While for slag with high alkalinity (CaO/SiO2 >2.0), the saturated MgO content will not be seriously affected by the FeO content, what’s more the slag will not erode much more refractories. Therefore, improve slag alkalinity can strongly protect refractories.

The service life of ladle is directly influenced by refining time, so it is important to improve steelmaking technology so that to shorten smelting time.

     The service life of ladle will be reduced by 3 -5 heats once shut down, so to achieve efficient production, the key is shortening smelting cycle. On the premise of using advanced technology to guarantee the best steel quality and the lowest total consumption, shorten the smelting cycle to the minimum, improve equipment and shorten shut down time.

Export Obstacle about Refractory Scrap

Because of the low price of refractory scrap, the market on such materials is huge around the world, while not everyone can manage to get what they want. 

Recently we Yilong Refractory receive some inquiries about used/rejected or defective refractories, such as fused cast AZS refractories (zirconia-corundum refractories). Even the customer has no requirement on size, or shipping date, it’s a little difficult for us manufacturers to supply such kind scrap to other countries. You may ask WHY.

Firstly, even the refractory scrap has much using potential, though it can’t be equal to end refractory product. Usually, the manufacturer will recycle the refractories and then put them into reusing. So the manufacturers are more likely to reutilize than exporting the materials.

Secondly, as we all know that the declaration to the customs is complex in many countries, especially China. So only in the case that the amount is very huge and all other trading information is ok, such as payment terms. Otherwise, the manufacturer may possibly not promise to supply. 

OK, that’s all my opinions. All your ideas are welcome, different, similar or the same. 

And for refractory and heat insulation products used in steelmaking, glass making, cement making, metallurgy, etc. Go to www.yilongrefractory.com

World Crude Steel Production in 2013

It is said by WSA that world crude steel production reached 1,607 megatonnes (Mt) for the year 2013, increased by 3.5% compared to 2012. Furthermore, the growth came mainly from Asia and Middle East while crude steel production in all the other regions decreased in 2013 compared to 2012. 

From the steel production data in WSA, it is concluded that refractory products are in higher demands in Asia and Middle East in the past year. The 2014 demands in those two regions are not still sure, increase and decrease are both possible, while there is no doubt that refractory and insulation products at a relativily stable and big quantity are required for steelmaking plants every month. Asia and Middle East are still main refractories market with much potential by now.

For more specific information about refractory and insulation products, such as firebrick, calcium silicate board, castable, mortar, etc, go to the www.yilongrefractory.com.

Refractory Scrap: A World-traded Commodity

To most, the word ‘scrap’ evokes visions of unwanted, discarded leftovers. However, to the refractory industry, scrap represents a vital resource that enhances all aspects of refractory making.

The recycling of scrap refractories is an indispensable part of modern refractory industry, improving the industry's economic viability and reducing environmental impact. The recycling of scrap reduces the need for bauxite which is also named aluminous soil, thus significantly reducing CO2 emissions, water and energy consumption and air pollution.

As a result of these efficiencies, refractory scrap is increasingly being regarded as a raw material for manufacturing new products worldwide. Such scrap has become a globally traded commodity. 

There’s a trend that more and more steelmaking companies prefer to purchasing refractory products which are made of scrap in order to reduce the manufacturing cost. To catch up with the trend, a lot of plants start to recycle the scrap and then put them into reusing. It’s not only good to the environment but also make steelmaking companies benefit from such an behavior. 

For more information about refractories and scrap, go to the www.yilongrefractory.com.

Refractory Materials

Refractory Materials

    The supply of refractory materials is a key issue for the world steel industry. Yilong Refractory manages refractories that widely used in steelmaking, metallurgy, glass making, cement making, ceramic making, etc.

    Iron ore and coking coal are used mainly in the blast furnace process of ironmaking. For this process, coking coal is turned into coke, an almost pure form of carbon, which is used as the main fuel and reductant in a blast furnace.

    Typically, it takes 1.5 tones of iron ore and around 450 kg of coke to produce a tone of pig iron, the raw iron that comes out of a blast furnace. Some of the coke can be replaced by injecting pulverized coal into the blast furnace.

    Scrap iron is mainly used in electric arc furnace steelmaking. As well as scrap arising from the making and using of steel, obsolete scrap from demolished structures and end-of life vehicles and machinery is recycled to make new steel. Around 500 million tones of scrap are melted each year.

    Refractory is a common material on the earth’s surface. Most refractories are located in China, carried to dedicated ports by rail, and then shipped to steel plants in Asia, Africa, South America and Europe.

    Sea freight is an element of major concern for steelmakers today, as the high demand for raw materials is causing backlogs at ports.

    To see more information about refractory products, go to the www.yilongrefractory.com.