what is grinding in cement

cement grinding unit | cement grinding plant | epc project

cement grinding unit | cement grinding plant | epc project

Cement grinding unit, or called cement grinding plant, is an individual grinding plant in the finished cement production. The new-type cement grinding units adopt pre-grinding technology. The cement grinding units not only reduce the particles of feeding materials, but also help to produce cracks and flaws inside the particles, which largely increase production capacity of cement mill, reduce the energy consumption.

The cement grinding machine includes cementdryer, cement ball mill, cement roller press, powder selecting machine, conveyor and other cement equipment. We can provide scheme design for free according to the requirements of users, and offer appropriate equipment to ensure smooth production with less investment and high profit.

The cement grinding process include the admixture crushing, cement batching station, pre-crushing, high and fine powder grinding, fine powder separation, dust treatment, automatic control and other technologies. The finished cement can meet the requirement for high yield, high quality and energy saving.

As a professional EPC project provider, we have the ability to provide the custom-design solutions to cement manufacturing for every client. Our solution covers all stages including equipment installation, operation, production, maintenance, we will send technicians to guide training, until the customer is satisfied.

For the structure, of the cement mill, we adopts the advanced obstructing equipment for internal powder, add the activated device to the fine grinding chamber, and there is the special grate plate at the end of the cement mill, which can reduce the size of the grinding medium, greatly improve the grinding efficiency, and achieve the purpose of high output and low energy consumption.

The cement grinding unit has advantages of simple structure, strong controllability, and easy to operate or maintain. The discharge concentration is less than 50mg/Nm3, lower than the discharge standard, and protect the environment of the production site effectively.

The production process overcomes the disadvantages of traditional equipment. The fineness of product is easy to be adjusted, apply for different requirement of fineness. The equipment also has advantages of large heat dissipation area and low temperature inside mill. The finished product of new-type cement grinding unit has high quality and large capacity.

As for the layout, the cement grinding unit is built near the sales market of cement. The most of cement admixture is the industrial residue, and cement grinding plant can greatly consume the industrial residues like slag, fly ash, slag, coal gangue. So the cement grinding unit brings green benefits well.

Traditional cement factories belong to high-pollution and high-energy consumption industries and do not meet the goals of energy conservation and consumption reduction in the development of modern industry. Cement grinding unit is a key link in cement plant. To achieve energy saving and consumption reduction in the cement industry, we must proceed from the cement grinding unit. Through a series of research and analysis, the following seven methods can effectively reduce the energy consumption of cement grinding plant.

Make full use of various industrial waste slags, such as blast furnace slag, steel slag, fly ash, and burned coal gangue. These waste slags are treated at high temperature and help to improve the performance of cement. At the same time, it also reduces the particle size of the grinding material, which can reduce the power consumption per unit product.

Under the fixed process conditions, when the 45m sieve residue and specific surface area of cement are controlled at a reasonable level, particles below 3m and above 45m can be limited, so as to obtain good cement performance and lower production costs. Compared with other methods, this fineness control method has the advantages of simple operation and effective control. As long as a sample is taken for a sieve analysis test and specific surface area determination, it can provide a basis for the operation of the cement mill.

In the cement grinding process, a small amount of admixture is added to eliminate the adhesion and aggregation of the fine powder, accelerate the grinding speed of the material, improve the grinding efficiency, and also increase the content of 3-30m by 10-20%, which is conducive to the high-quality, energy-saving and high-yield of cement ball mill. Such additives are collectively referred to as grinding aids. In most cases, the use of grinding aids can increase the output of the cement ball mill without changing the cement production process, the purpose of improving the quality of cement production line, reducing costs, and producing green high-performance environmentally friendly cement can be achieved.

In the cement production process, the use of new technologies and processes can greatly reduce energy consumption, save investment, and achieve economic benefits. Such as multi-point feeding, multi-point retrieving, circulating grinding process; extruder combined grinding process, etc. At the same time, we must vigorously promote to use energy-saving cement grinding equipment. For example, instead of traditional cement ball mills, select new type cement vertical mills, trapezoidal mills, and other energy-saving cement grinding equipment.

At present, these two measures are the main reform directions for the cement mill optimization. The following effects can be achieved: the output is increased by 30% -60%, the power consumption is reduced by 25% -40%, and the power consumption per ton of cement is reduced by 8-12kWh. It can effectively increase the strength of cement. Generally speaking, the strength of cement can be increased by more than 5MPa.

Frequency conversion technology is one of the energy-saving technologies. This technology can help some auxiliary equipment in cement plant to save energy, such as fans, batching metering, and variable-speed equipment. At the same time, it also meets the characteristics of low-speed operation and large starting torque of the cement ball mill and realizes the continuous adjustment of the running speed of the cement ball mill. There is no inrush current when the motor starts, the starting distance is sufficient, and the protection function is perfect. Ensure the quality of process control and save maintenance costs.

The use of low-voltage motor full-phase control technology, it has the advantage of automatically adjusting the output power of the motor when the load is lightly loaded and heavily loaded so that the motor can save electricity by 15% at the time. Adopt a green lighting system, through these technical measures, greatly improve the power factor, reduce the reactive power demand, and reduce the loss of active power.

In general, correctly coordinating the relationship between quality, output, and the energy consumption is the basic way for cement grinding to save energy and reduce consumption. Traditional cement mills have low energy utilization rate and do a lot of useless work. The energy-saving technology should be the basic task of transforming the cement grinding process, and all these need to be established on the basis of a certain quality index control. To achieve a reasonable particle ratio of cement materials, it should meet the gradation requirements of performance, and add an appropriate amount of industrial waste residue.

cement-grinding-plant

cement-grinding-plant

Description The cement grinding station with an annual output of 1 million tons adopts the technology of separately grinding clinker and slag, among which the clinker grinding adopts the combined grinding process composed of two 4.2m 13m cement mills. The production process of the grinding station is stable, achieving the goal of high quality, high yield and low consumption.

This 500,000t/y cement grinding station is constructed in Russia. Jiangsu Pengfei Groupundertakes the construction of this cement grinding line from Star River Industrial Development Co., Ltd. which is in the Economic Cooperation Zone of Heihe City in Heilongjiang Province. Pengfei is responsible for the process design of the whole project.

This 2,000,000 t/y cement grinding station or cement grinding machine could serve concrete mixing plants and concrete pipe pile factories. It could also be used in industrial construction project and civil construction project. Jiangsu Pengfei Group provides complete project plan and process equipment. It is an independent and complete cement production line including cement grinding, bulk packaging, and packaging and delivering.

Pengfei Group provides the complete project plan of this 1000000 tons/year slag powder production line. We also manufacture process equipment of this production line. We adopt a close circuit grinding system consist of 1400450 roller press, 3.813m ball mill, and 0-SEPA3000 separator. We set six1018m powder storage silos for this slag powder processing equipment. The total storage capacity is 6000 tons. We have four 220 m3/min oil-free lubricating air compressors to provide compressed air. Compressed air is dried and purified by dryer and water oil separator.

raw materials in cement production

raw materials in cement production

Each of these materials has different grinding coefficient. The higher grinding coefficient, the more grinding of this material. The grinding factors for base raw materials in cement production are given in table below.

Corrective additives are added in cases where the chemical composition of the raw mix does not meet the established requirements. For example, sand, tripoli are used to increase silica. With a lack of iron oxide to reduce the clinker sintering temperature and increase the saturation coefficient, add pyrites cinder, iron ore. This results in saving gas during burning. Carbonate and clay components are used to provide the necessary content of CaCO3. They have different carbonate components of CaCO3 (titer).The carbonate component contains up to 97% CaCO3, clay contains about 10%. It is necessary to achieve, for example, a titer of 80%. Therefore, there are sludge pools with high and low titer content on cement plants. The sludge from pools is mixed in certain proportions.

That is why high quality grinding balls with high hardness over the entire section are used during grinding materials in tube mills in this industry. During 10 years Company Energosteel has been supplying grinding balls to cement plants not only in Ukraine, but also abroad.

clinker grinding in cement production

clinker grinding in cement production

Earlier we considered a mixture of which materials is used in cement production. The base of this mixture is a clinker. In this article, we will consider the composition of clinker and its impact on grinding balls deterioration in milling process.

Clinker (in cement industry) is transitional product in cement production. Upon heating mixture obtained from limestone (about 75%) and clay (about 25%) partial melting occurs and clinker granules are formed. Clinker and gypsum (about 5 %) are mixed and finely milled to obtain cement. Gypsum control the setting properties of the cement. It can be partially replaced by other forms of calcium sulfate. Some technical conditions allow adding other materials. A typical clinker has an approximate composition: CaO -67%, SiO2 22%, Al2O3 5%, Fe2O3 3%, and 3% of other components.

Factor of clinker saturation (KSK) characterizes the incomplete saturation of silica with calcium oxide during clinker formation. It calculated from the ratio of the difference in total CaO content without the sum of Al203 + Fe203 and S03 to the Si02 concentration with the corresponding coefficients the molar ratios of each oxide to CaO.

Value KSK = 92 % indicates that clinker is medium grinded, KSK > 92% easy to grind, KSK <92% hard to grind. The lower value KSK, the larger the clinker. Typical KSK values in Portland cement clinker are 0.8-0.98, or 80-98%. The value KSK of ordinary Portland cement is 90-95% and 95-98% of high strength Portland cement. The higher value KSK, the lower the grindability.

In addition to the physical and chemical characteristics of clinker, the required grinding degree (grinding fineness) also affects grinding balls deterioration. Blaines specific surface area (cm2 / g) mainly used abroad. Sieve residue (in percentage) used in Ukraine and CIS. In modern conditions, the laboratories of many cement plants use both indicators. Their dependence is shown below in the graph.

Clinker grindability is determined by quantity of electricity consumed for grinding (kW / ton) under other equal conditions. In cement production entire crushing and grinding process consumes about 85% of the electricity. At the same time 75% of electricity consumed for milling and only 2-20% of them consumed for grinding. According to some hypotheses, only a thousandth blow of the ball is spent on grinding the material. Thus, cement plants are among the most demanding for grinding balls quality customers of company Energosteel.

what is the role of lime in cement?

what is the role of lime in cement?

Lime has been used as a binder in mortars for over 2000 years. Today, lime is still used as the primary binder in many mixes, usually in the form of lime putty or Hydraulic lime. Hydrated lime is used in modern cement based mortars mainly for its properties as a plasticiser.

Furthermore, does lime strengthen concrete? Lime when added to Reinforced cement concrete makes a good base for load bearing walls, columns, or laying under floors because it has a degree of flexibility that regular concrete does not. It also has a certain waterproof property to it that prevents subsoil dampness in floors and walls.

Hydrated lime improves the strength of the mortar by several mechanisms: Carbonation - Hydrated lime reacts with carbon dioxide in the atmosphere to form limestone. Cementitious Reactions - Pozzolonic reactions can occur between hydrated lime and silica compounds in the mortar mix.

Lime hardens much more slowly than cement-containing mortars, making it much more workable. Lime is also less brittle and less prone to cracking, and any cracked areas can absorb carbon dioxide and mend over time. Cement hardens very quickly, but may be too strong for some applications, e.g., working with old bricks.

concrete grinding - how much will a concrete grinder remove?

concrete grinding - how much will a concrete grinder remove?

Lets go deeper into details. Concrete grinding is a mechanical treatment process of the surface using special equipment, like Husqvarna or HTC, combined with abrasive diamond tools. The metal segment attachments procure the removal of unevenness on rough concrete surfaces to reveal a smooth finish. There are grinding diamond tools to help make the process faster.

Have you ever been struggling to remove old mastic or glues, waterproofing membranes, or epoxy coatings from a concrete surface? Its a bit of a challenge most concrete resurfacing contractors, fluid floor applicators, and even waterproofers have. The main goal is to simplify the methods of removing materials from concrete surfaces. Thus, preparation to reapply a coating, membrane, or adhesive will be enjoyable and fun.

A small planetary concrete grinder with basic grinding tools will remove around 1/16 of the concrete in 1-2 passes in a normal situation. You might be able to remove more 1/8 if use a heavier concrete grinder and more aggressive PCD tools. In fact, an angle grinder with a cup wheel will do the best job.

Lastly, the more pressure you put on the grinder, the more wear you put on the diamond tools. If you need to remove a thicker layer of concrete faster, you may need an extremely soft bond grinding pad.

In fact, concrete grinding contractors normally charge around $0.75-$2 per square foot for light concrete sanding. This makes the floor ready to install a new floor covering. Moreover, check out the ranges for different types of glues or mastic removal:

The beauty of choosing a full exposure aggregate of polished concrete for your space whether residential or commercial. Is that you got a truly unique floor. No two concrete floors are the same, as it all comes down to concrete quality, technique, and aggregate amount.

However, most people dont know how to achieve that shiny and refine style. Also, aggregate exposure ranges from minimal to open-stone exposure depending on the depth of the rocks inside the concrete and grinding.

Firstly, your best option to find out the floor prep cost in your area is to contact a contractor. Secondly, request a Free Estimate to find out the best competitive price from your Concrete Contractors Near Me. Lastly, if youre getting into the game of floor renovation, hiring a Pro will most likely help to avoid wasting time and money on your first few jobs.

cement manufacturing process | phases | flow chart | cement | engineering intro

cement manufacturing process | phases | flow chart | cement | engineering intro

Cement is the basic ingredient of construction and the most widely used construction material. It is a very critical ingredient, because only cement has the ability of enhancing viscosity of concrete which in returns provides the better locking of sand and gravels together in a concrete mix.

Cement uses raw materials that cover calcium, silicon, iron and aluminum. Such raw materials are limestone, clay and sand. Limestone is for calcium. It is combined with much smaller proportions of sand and clay. Sand & clay fulfill the need of silicon, iron and aluminum.

Generally cement plants are fixed where the quarry of limestone is near bye. This saves the extra fuel cost and makes cement somehow economical. Raw materials are extracted from the quarry and by means of conveyor belt material is transported to the cement plant.

There are also various other raw materials used for cement manufacturing. For example shale, fly ash, mill scale and bauxite. These raw materials are directly brought from other sources because of small requirements.

Before transportation of raw materials to the cement plant, large size rocks are crushed into smaller size rocks with the help of crusher at quarry. Crusher reduces the size of large rocks to the size of gravels.

The raw materials from quarry are now routed in plant laboratory where, they are analyzed and proper proportioning of limestone and clay are making possible before the beginning of grinding. Generally, limestone is 80% and remaining 20% is the clay.

Now cement plant grind the raw mix with the help of heavy wheel type rollers and rotating table. Rotating table rotates continuously under the roller and brought the raw mix in contact with the roller. Roller crushes the material to a fine powder and finishes the job. Raw mix is stored in a pre-homogenization pile after grinding raw mix to fine powder.

After final grinding, the material is ready to face the pre-heating chamber. Pre-heater chamber consists of series of vertical cyclone from where the raw material passes before facing the kiln. Pre-heating chamber utilizes the emitting hot gases from kiln. Pre-heating of the material saves the energy and make plant environmental friendly.

Kiln is a huge rotating furnace also called as the heart of cement making process. Here, raw material is heated up to 1450 C. This temperature begins a chemical reaction so called decarbonation. In this reaction material (like limestone) releases the carbon dioxide. High temperature of kiln makes slurry of the material.

The series of chemical reactions between calcium and silicon dioxide compounds form the primary constituents of cement i.e., calcium silicate. Kiln is heating up from the exit side by the use of natural gas and coal. When material reaches the lower part of the kiln, it forms the shape of clinker.

After passing out from the kiln, clinkers are cooled by mean of forced air. Clinker released the absorb heat and cool down to lower temperature. Released heat by clinker is reused by recirculating it back to the kiln. This too saves energy.

Final process of 5th phase is the final grinding. There is a horizontal filled with steel balls. Clinker reach in this rotating drum after cooling. Here, steel balls tumble and crush the clinker into a very fine powder. This fine powder is considered as cement. During grinding gypsum is also added to the mix in small percentage that controls the setting of cement.

Material is directly conveyed to the silos (silos are the large storage tanks of cement) from the grinding mills. Further, it is packed to about 20-40 kg bags. Only a small percent of cement is packed in the bags only for those customers whom need is very small. The remaining cement is shipped in bulk quantities by mean of trucks, rails or ships.

Widely used in highways, utilities, construction and other industries washing, grading, cleaning, as well as fine-grained and coarse-grained materials processing and other operations, the construction and gravel roads are particularly suitable. We feel proud to present ourselves as the well renowned importer and exporter of different Optimum Quality Engineering Equipments. Each and every product, forming part of our exquisite collection, has to go through different stringent quality checks so as to ensure that only finest quality product ultimately reaches the market.

what is ppc cement | uses of portland pozzolana cement | types of pozzolana materials | properties of portland pozzolana cement | advantages & disadvantages of portland pozzolana cement

what is ppc cement | uses of portland pozzolana cement | types of pozzolana materials | properties of portland pozzolana cement | advantages & disadvantages of portland pozzolana cement

Portland Pozzolana cement is an incorporated cement produced in that certain ratio by the synthesis and characterization of OPC cement from pozzolana materials. Its also generally referred to as PPC cement.

PPC type cement is a form of Portland cement distinguished by the existence of pozzolana particles such as fly powder, volcanic ash, that is applied to OPC by 15percent to 35%.Cement is accessible in every grade. It is indeed finer and far less dense than the OPC.

The inclusion of pozzolana particles contributes to the production of cement, which uses less OPC but has greater longevity and strength. PPC grade cement does have a greater settling period as well as a lower compressive strength initially. Even so, the very same outcomes as OPC are considered to be obtained in the long term.

It is usually used for the building of marine systems, masonry mortars including hydraulic structures. These are widely found in mass concrete works such as dikes, sewer tanks, dams, respectively. In certain instances, PPC cement grade must be used in replacement of OPC.

Pozzolanic materials are siliceous as well as aluminous materials, having very little if any cementitious quality of their own, but also in finely separated form and even in the presence of water, respond chemically with calcium hydroxide produced at normal temperature by hydration process to form compounds possessing cementitious properties.

Siliceous or aluminum compounds in a finely separated shape react with calcium hydroxide in order to form extremely stable, cemented substances of a diverse structure containing calcium, silica, and water.

Usually, amorphous silicate reacts even quicker than that of the crystalline form. Calcium hydroxide, a water-soluble substance, is transformed through an insoluble cement either by process of pozzolanic materials.

Originally, the pozzolanic reaction occurs and therefore the processing of hydration heat as well as the formation of power is also slow. The reaction requires the absorption of Ca(OH)2 and therefore there is no output of Ca(OH)2. The reduction in Ca(OH)2 improves the toughness of cement paste by making cement paste thick and impervious.

Natural pozzolanis a raw or calcinednatural materialthat showspozzolanic properties. Volcanic ash or pumicite, tuffs, shales, and opaline cherts and diatomaceous earth are examples of natural pozzolans.

Silica Fume: That is an artificial pozzolanic product. Its also created by the reduction of high-quality quartz using coal inside an electric arc furnace in the manufacturing of silicon or ferrosilicon alloys. Silica smoke rises as oxidized gas in the method. It melts, compresses, and gathers in fabric bags. The silica smoke so obtained has been further treated to extract impurities and also to monitor the size of the particles.

Fly ash: This is a finely separated residue from its burning of powdered coal. This is a waste material of coal-fired power plants and railway locomotives, respectively. It was the most popular artificial pozzolana material. Fly ash crystals are spherical being of the same fineness as cement. Silica is also still easily accessible for a reaction.

Pozzolanic activity of fly ash is pleasant, although it is important that this has a steady carbon content as well as a constant fineness. Its use of fly ash in concrete as a blend not just to adds technological benefit to the properties of concrete, but also leads to the prevention of environmental emissions.

Blast furnace slag: The replacement of cement with ground granulated blast furnace slag has been found to diminish the measure of water in the new concrete to acquire a similar droop. The decrease in water substance will be more with the increment of slag substance and fineness of the slag. This is because of the various designs and state of slag and cement particles. Further the water added for blending isnt promptly lost because of the slight lower surface hydration of slag than cement.

The production process is roughly the same as ordinary Portland cement,which can be separated into four processes: crushing of raw materials, grinding of raw materials, calcination of clinkers, and grinding of cement.

PPCgradecementis a type of Portlandcementcharacterized by the presence of pozzolana particles like fly ash, volcanic ash which is added to OPC in the ratio of 15% to 35%. Thecementis available in any specific grades. It is finer and less dense than OPC.

It can be confidently employed in construction of hydraulic structures, marine works, mass concreting such as dams, dykes, retaining walls foundations, and sewage pipes. It is also suitable for usein commonapplicationssuch as masonry mortars and plastering.

PPC Grade Cement (Portland Pozzolana Cement): PPC grade cement is a type of Portland cement characterized by the presence of pozzolana particles like fly ash, volcanic ash which is added to OPC in the ratio of 15% to 35%. The cement is available in any specific grades. It is finer and less dense than OPC.

The hydraulic cementitious materials made of Portland cement clinker, pozzolanic material, and a proper amount of gypsum are all called Portland pozzolana cement (PPCcement). It is a kind of blended cement which ismanufacturedby mixing and fine-grinding silicate cement clinker, pozzolanic material, and gypsum.

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