Technological advances, growing competition, and volatile energy markets are continually squeezing the profits of many Portland cement manufacturers. Except to upgrade the cement manufacturing plant, some cost-saving tips play the same role in helping cement enterprises get out of difficulties and increase profits.
There are some effective methods to realize cost saving in cement production processes, such as the improvement of raw materials’ structure, the secondary use of waste heat, the adoption of frequency conversion speed regulation technology, etc. If you are worried about the profitability of your cement business, maybe you can find useful suggestions here.
Tip 1: Optimize the Raw Material Structure
Limestone is the main material for cement manufacturing. Using industrial residue to replace part of limestone can greatly save production costs and achieve the effect of energy saving and emission reduction. At present, many industrial residues are containing CaO, such as carbonization slag, steel slag, etc. These residues have been treated at high temperatures so the CaO inside has been converted into silicate, aluminate, or ferrite. They are unnecessary to be calcined at high temperatures to decompose CaCO3 like limestone. Practices show that the energy consumption for decomposing CaCO3 in limestone accounts for more than 50% of the clinker calcination heat consumption.
Tip 2: Improve Grinding Technology & Add Grinding Aids
The grinding process is the main energy consumption link in cement manufacturing, which includes raw materials grinding and clinker grinding. In this part, we can greatly improve the grinding efficiency and output, as well as reduce the power consumption by adopting advanced grinding equipment and adding grinding aids appropriately.
Cement vertical mill is a kind of high-efficiency and closed-circuit grinding equipment, which integrates crushing, drying, grinding, and grading functions. In recent years, it has been widely used in new dry cement production lines and gradually replaced ball mill as the main cement equipment in large cement plants. It not only has a high energy utilization rate and simple process, but also features strong drying capacity, short residence time of materials, and easy control of process parameters. In terms of the working environment, the noise of the vertical mill is 10 dB lower than that of the ball mill. Besides, it can also use the waste heat from kiln head or kiln tail to dry raw meal for decreasing energy consumption.
| Model | Grinding disc diameter (mm) | Roller diameter (mm) | Feeding size (mm) | Capacity (t/h) | Main motor power (kw) | Disc rotation speed (r/min) | Weight (t) |
| LM0806 | 800 | 600 | <30 | 3-5 | 75 | 62 | 13. 8 |
| LM1311 | 1300 | 1100 | <40 | 9-15 | 200 | 43 | 46. 5 |
| LM1512 | 1500 | 1250 | <40 | 10-19 | 280 | 43 | 65 |
| LM1714 | 1700 | 1400 | <42 | 13-32 | 400 | 40 | 90 |
| LM2215 | 2250 | 1560 | <50 | 25-45 | 800 | 32 | 120 |
| LM2820 | 2800 | 2000 | <65 | 35-80 | 960 | 32 | 200 |
| LM3424 | 3450 | 2400 | <70 | 60-100 | 1350 | 30 | 300 |
| LM4831 | 4800 | 3150 | <115 | 95-200 | 3150 | 26 | 760 |
| HRM1411 | 1400 | 1185 | <35 | 10-15 | 225 | 37. 96 | 49 |
| HRM1612 | 1600 | 1200 | <40 | 12-20 | 280 | 36. 16 | 65 |
| HRM1813 | 1800 | 1300 | <45 | 16-28 | 350 | 34 | 78 |
| HRM2115 | 2100 | 1500 | <50 | 20-35 | 400 | 31.6 | 87 |
| HRM2215 | 2250 | 1570 | <60 | 25-35 | 500 | 31 | 92 |
| HRM2417 | 2450 | 1750 | <70 | 28-40 | 630 | 29. 5 | 114 |
| HRM2619 | 2650 | 1900 | <75 | 35-55 | 710 | 28.1 | 132 |
| HRM3123 | 3150 | 2300 | <80 | 40-80 | 1120 | 25 | 210 |
| HRM3424 | 3450 | 2430 | <80 | 52-85 | 1300 | 24. 5 | 310 |
| HRM3626 | 3600 | 2650 | <80 | 60-100 | 1950 | 24 | 450 |
| HRM4028 | 4000 | 2850 | <90 | 70-115 | 3100 | 22. 9 | 600 |
| HRH4230 | 4250 | 3050 | <100 | 85-160 | 3400 | 22. 18 | 680 |
| HRM4531 | 4500 | 3150 | <110 | 95-200 | 3600 | 21.5 | 750 |
Grinding aids is an additive used to improve grinding efficiency. It has the advantages of less investment and quick effect. Adding a small amount of grinding aids in the grinding process can affect its mechanical and chemical processes so as to improve the grinding efficiency and physical properties of cement.
Tip 3: Adopt Frequency Conversion Speed Regulation Technology
Frequency conversion speed regulation technology plays an important role in energy-saving control of cement auxiliary equipment. The most representative is the control of fan power consumption. According to statistics, about 30% of the power consumption for producing 1 ton cement is used for fans. Using frequency control technology can save electricity about 2.5 kW · h/ t, equivalent to 1 kg standard coal. It greatly reduces the cost of cement production.
Tip 4: Use Cement Kiln to Treat Waste Materials
Waste materials produced in the cement production process are usually treated at a high temperature to achieve harmlessness, that is, they should be kept at 1 000 ℃ for at least 2 s. Because the temperature of the cement kiln is commonly kept above 1 000 ℃, and the alkaline substances inside the kiln can act as a neutralizer to stabilize some harmful substances then reduce the generating of dioxins. Therefore, a cement kiln can also be used as a waste treatment device. Waste materials will be discharged safely after staying in the kiln for about 8 s. In a cement production line of 3 000 t / a, the cement kiln can treat nearly 10 × 104 tons of waste, basically realizing the cost-saving and waste material harmlessness.
Tip 5: Secondary Use the Waste Heat
The secondary use of the resource is also a way to save costs. Its concrete embodiment in the cement manufacturing process is the reuse of waste heat. In cement plants, we usually use the waste heat of cement kiln to generate electricity, dry materials, heat the kiln secondary air and the furnace tertiary wind, etc. In this way, cement manufacturers can not only reduce electricity consumption but also realize energy saving and emission reduction. At present, this method is mostly applied in large dry process cement plants.
Conclusion
Through the above 5 tips, Portland cement manufacturers can achieve cost savings from each stage of the cement production process. Of course, there are many other ways, which requires us to constantly discover and practice in the production process. If you are interested in Portland cement manufacturing, please feel free to contact us! Hope you enjoy my sharing and get useful information.
