Calcium Hydroxide Production Line
Function Description：The core equipment of a calcium hydroxide production line includes a lime slaker, water mist dust collector, hydrated lime classifier, and calcium hydroxide grinding mill, supporting the customized production of various grades of calcium hydroxide.
Suitable Materials：Calcium hydroxide (slaked lime or hydrated lime)
Calcium Hydroxide Production Line Introduction
The calcium hydroxide production line developed by Guilin Mining Machinery is an all-in-one production line specially designed for the characteristics of calcium hydroxide such as easy adhesion and agglomeration. Its core equipment includes Lime Slaker, Water Mist Dust Collector, Calcium Hydroxide Air Classifier and calcium hydroxide grinding mill. Adopting Distributed Control System (DCS), it realizes precise and controllable finished product fineness from 80 mesh to 800 mesh. The equipment volume and finished output can be custom-designed (5~50t/h). It can produce high-purity (≥96%), high-fineness (325 mesh sieve passing rate ≥98%) and high-activity calcium hydroxide to meet customized production requirements of calcium hydroxide powder of various grades (industrial, environmental protection, food, pharmaceutical, etc.).
Features & Advantages of Calcium Hydroxide Production Line
The calcium hydroxide production line is mainly composed of digestion, dust removal, classification, grinding and control systems. It adopts two-stage digestion design and multi-dust removal technology combining pulse and water mist. The digestion rate reaches over 98%, waste gas emission ≤10mg/m³ and waste water emission close to zero. The production capacity and volume can be customized. The investment cost is significantly lower than that of the traditional 3~7 stage process (reduced by more than 30%). The whole system is designed for calcium hydroxide properties, which can flexibly produce high-purity, high-fineness and high-activity calcium hydroxide powder to meet customized demands of different customers.
Digestion System: Lime Slaker
The Lime Slaker adopts combined digestion modules and two-stage digestion design with customizable capacity and volume. It greatly cuts investment costs for steel frames, foundations and workshops. It features strong heat preservation capacity and high digestion efficiency (≥98%), superior to traditional digesters with 3~7 stage design. High-activity calcium hydroxide is produced by precisely controlling the water-lime ratio.
Dust Removal System: Water Mist Dust Collector
It adopts patented pulse water mist dedusting technology. Pulse baghouse dust collector works in tandem with Water Mist Dust Collector and they are connected in series with Lime Slaker. It recovers heat to promote digestion reaction while ensuring good dust removal effect. Through multi-stage dedusting technology and recycling of water resources, ultra-low emission is achieved (waste gas emission ≤10mg/m³, waste water emission close to zero).
Classification System: Calcium Hydroxide Air Classifier
Calcium Hydroxide Air Classifier adopts advanced pre-classification process. It can directly classify digested calcium hydroxide without grinding, solving the ineffective grinding and over-grinding problems of traditional process that grinds before classification. Combined with calcium hydroxide grinding mill, it can flexibly build customized production lines to meet production requirements of calcium hydroxide powder of different grades (industrial, environmental protection, food, pharmaceutical, etc.).
Grinding System: Calcium Hydroxide Grinding Mill
The calcium hydroxide grinding mill is specially developed and modified for calcium hydroxide characteristics. It integrates dispersion, grinding and classification functions. With full-process anti-sticking design and triple dispersion technology, it easily solves the problems of calcium hydroxide such as easy agglomeration, blockage, adhesion and compaction. The finished particle size is precisely controllable, making it the core equipment for producing calcium hydroxide with high fineness, high purity and high specific surface area.
Control System: Distributed Control System
Distributed Control System (DCS) is adopted to realize centralized intelligent control. The system supports one-click or zonal start-stop, fault early warning and linked shutdown functions. It has an intuitive interface displaying maintenance reminders and production statistics. The logic modules are reasonably arranged with simple operation procedures, which reduces labor cost and risk of shutdown caused by misoperation, and comprehensively improves production efficiency.
Process Flow of Calcium Hydroxide Production Line
Raw Material Handling
High-quality limestone with calcium carbonate content ≥90% is generally used as raw material. It is coarsely crushed by jaw crusher to ensure particle size for kiln calcination (≤50mm; oversized particles are unfavorable for calcination). Then vibrating screen, magnetic iron remover and other equipment are used for screening and impurity removal to guarantee the whiteness and purity of finished calcium hydroxide powder.
Jaw Crusher (Left), Magnetic Iron Remover (Middle), Vibrating Screen (Right)
Calcination and Crushing
Limestone (CaCO₃) → Quicklime (CaO) + CO₂↑
Pretreated limestone enters rotary kiln or vertical kiln for high-temperature calcination. The temperature is generally controlled between 900°C~1350°C. Too low calcination temperature leads to underburning and incomplete decomposition of limestone, affecting quicklime purity. Excessively high temperature causes overburning of limestone, reduces specific surface area and lowers quicklime activity.
Quicklime discharged from the kiln after calcination has inconsistent particle size and needs further crushing and screening to ensure particle size ≤30mm. The particle size and purity of calcined quicklime directly affect the efficiency of lime slaking reaction and determine the quality of finished calcium hydroxide powder.
Ca(OH)₂ (Calcium Hydroxide Slurry) + CO₂ (Purified Gas) → CaCO₃ (Precipitated Calcium Carbonate) + H₂O
Carbon dioxide generated from limestone calcination itself is non-toxic and harmless, but massive emission will trigger greenhouse effect and damage the environment. It can be purified and reused to produce precipitated calcium carbonate (PCC), so as to improve economic benefits.
Rotary Kiln (Left) and Vertical Kiln (Right)
| Comparative Analysis of Rotary Kiln and Vertical Kiln | |
| Rotary Kiln | Vertical Kiln |
| Limestone rolls and advances in the slowly rotating inclined kiln body and contacts high-temperature gas flow for calcination | Limestone and fuel move from top to bottom inside the static kiln body under gravity for calcination |
| Materials tumble continuously with uniform heating, basically no overburning or underburning | Materials tend to accumulate at the bottom with poor uniformity, prone to overburning and underburning |
| Clean fuels such as natural gas and pulverized coal are used and isolated from materials, almost no pollution risk | Fuel mixes directly with materials, bringing pollution risk and reducing quicklime purity |
| Materials collide during tumbling to remove partial surface impurities | Static combustion, impurities attached to materials are hard to remove |
| Purity of calcined quicklime ≥95%, high and stable purity | Purity of calcined quicklime 85~95%, relatively low purity with large fluctuation |
| Suitable for high-purity demanding fields including environmental protection, desulfurization, food, medical treatment and high-end industry | Suitable for fields with low purity requirements such as construction mortar, iron & steel smelting and general industry |
Digestion & Curing
Quicklime(CaO) + Water（H₂O） → Calcium Hydroxide（Ca(OH)₂） + Heat
Calcined quicklime is continuously, evenly and quantitatively fed into Lime Slaker via constant feeder. Precise control of water-lime ratio, reaction time, reaction temperature and stirring intensity realizes quicklime digestion, curing (homogenization + aging) and deep digestion.
The mass ratio of water to quicklime is generally mixed at 0.6:1 to 0.8:1, and the reaction temperature is controlled between 80°C~95°C. A twin-shaft agitator is adopted for high-speed stirring in primary digestion. Gentle and slow homogenization is applied to achieve even distribution of moisture and heat. Digestion time and aging time depend on quality requirements of finished calcium hydroxide powder; longer time does not always mean better quality.
Conventional Process: Twin-shaft agitator serves as primary digestion tank for preliminary digestion, and single-shaft agitator is used for curing (auxiliary supplementary digestion).
Two-stage Digestion Process: Twin-shaft agitator acts as primary digestion tank for preliminary digestion, and chain stirring digester realizes curing and deep digestion, generally applied to produce high-activity and high specific surface area calcium hydroxide.
Water Mist Dust Removal
Lime slaking reaction generates a large amount of hot steam and calcium hydroxide dust. Direct emission into air will cause white pollution and harm the environment. Pulse dust collector is generally used first to filter dust, reduce the load of subsequent Water Mist Dust Collector and prevent agglomeration and blockage of calcium hydroxide dust.
The pre-filtered waste gas is then sprayed and washed by Water Mist Dust Collector for water mist dedusting. Hot water at 60~80°C is recovered and fed into Lime Slaker to promote digestion reaction, while hot water ≤60°C returns to Water Mist Dust Collector for spray washing together with a small amount of supplementary water (3%~5%). It achieves high water resource utilization rate and nearly zero wastewater discharge. With multi-stage dedusting technology, waste gas emission concentration is stably controlled ≤10mg/m³.
Classification and Grinding
Digested calcium hydroxide is conveyed by conveying equipment into Calcium Hydroxide Air Classifier or calcium hydroxide grinding mill for processing. According to requirements on fineness, purity and high specific surface area of finished calcium hydroxide powder, Calcium Hydroxide Air Classifier and calcium hydroxide grinding mill can be flexibly equipped to realize customized production of calcium hydroxide powder of different grades.
Conventional Production Line: Calcium Hydroxide Air Classifier is generally adopted for classification; coarse powder is directly discharged. It features simple process and low investment cost, suitable for scenarios with low requirements on purity and fineness of calcium hydroxide powder, such as construction mortar, wall putty powder and other construction fields.
Industrial Grade Production Line: Calcium hydroxide grinding mill is generally used for grinding and classification. The finished calcium hydroxide powder has uniform purity and fineness, suitable for general industrial manufacturing such as plastics and rubber.
Environmental Grade Production Line: Calcium Hydroxide Air Classifier is generally used for classification. Under-reacted coarse powder needs to return to Lime Slaker for further digestion. The finished calcium hydroxide powder has high activity and fast reaction rate with specific surface area usually ≥17m²/g, applicable to common environmental fields such as power plant desulfurization and wastewater treatment.
Food & Pharmaceutical Grade Production Line: Calcium Hydroxide Air Classifier is generally used for classification and calcium hydroxide grinding mill for fine grinding and classification. The finished calcium hydroxide powder has high purity and high fineness, suitable for high-end fields such as food and pharmaceutical industry.
Packing and Storage
Finished calcium hydroxide powder has strong hygroscopicity and is prone to deterioration by absorbing moisture and carbon dioxide. Sealed moisture-proof packaging is required. It shall be stored in cool, dry and well-ventilated warehouses with moisture-proof layer laid on the ground. Mix storage with acids and oxidants is strictly prohibited.
Application Scenarios of Calcium Hydroxide Production Line
| Application Scope of Calcium Hydroxide Powder | |||
| Property | Fine Calcium Hydroxide | High-Activity Calcium Hydroxide | Ordinary Calcium Hydroxide |
| Purity | ≥96% | ≥94% | ≥90% |
| CaCO₃ Content | ≤3% | ≤4% | ≤5% |
| Specific Surface Area | No requirement | ≥17m²/g | No requirement |
| Fineness | 325 mesh sieve passing rate ≥98% | 325 mesh sieve passing rate ≥95% | 200~325 mesh |
| Whiteness | ≥90 | No requirement | ≥80 |
| Application Fields | High-end fields such as food and pharmaceutical industry | High-end environmental fields such as heavy metal pollution treatment | General industrial and environmental fields such as plastics and metallurgy |
| * The above data is for reference only; there is no unified industry standard for calcium hydroxide powder parameters | |||
Technical Parameters of Calcium Hydroxide Production Line
| GK Calcium Hydroxide Production Line Parameter Comparison Table | |
| Quicklime Particle Size (After Calcination) | ≤30mm |
| Finished Output | 5~50t/h |
Finished Fineness | 80~800 mesh (600 mesh ≥95%) |
| Finished Purity | 90%~98% |
Specific Surface Area | 0~15m²/g (Ordinary Calcium Hydroxide) |
| ≥17m²/g (High-Activity Calcium Hydroxide) | |
| Dust Emission | ≤10mg/m³ |
| Digestion Equipment | Lime Slaker |
| Dust Removal Equipment | Pulse Baghouse Dust Collector, Water Mist Dust Collector |
| Classification Equipment | Calcium Hydroxide Air Classifier |
| Grinding Equipment | Calcium Hydroxide Grinding Mill |
| Control System | Distributed Control System (DCS) |
| * The above data is for reference only, actual parameters vary with raw materials | |
| GK Calcium Hydroxide Production Line Parameter Comparison of Different Processes | |||
| Process Mode | Process Features | Capacity (t/h) | Total Power (kW) |
Conventional Production Line | Low requirements for purity and fineness | 5~10 | 370 |
Industrial Grade Production Line | Uniform purity and fineness | 10~15 | 412.7 |
| Environmental Grade Production Line | High activity and fast reaction rate | 10~15 | 570.1 |
| Food & Pharmaceutical Grade Production Line | High purity and high fineness | 10~15 | 746.35 |
| * The above data is for reference only, actual parameters vary with raw materials | |||
Frequently Asked Questions about Calcium Hydroxide Production Line
How to produce high-quality calcium hydroxide?
Raw Material Handling: Select high-quality limestone with calcium carbonate content ≥90%, and carry out pretreatment including crushing, screening and impurity removal to ensure feeding particle size ≤50mm. Adopt rotary kiln for calcination to guarantee the purity of calcined quicklime ≥95%, so as to ensure whiteness and purity of finished calcium hydroxide powder.
Digestion Process: Crush and screen calcined quicklime to ensure particle size ≤30mm, and adopt two-stage designed Lime Slaker (twin-shaft agitator + chain stirring digester). Precisely control water-lime ratio, reaction temperature, stirring length and reaction time to improve calcium hydroxide activity.
Dust Removal Process: Adopt Water Mist Dust Collector to prevent dust pollution, promote digestion reaction and increase total yield of high-quality calcium hydroxide powder.
Classification Process: Use Calcium Hydroxide Air Classifier for classification, then apply calcium hydroxide grinding mill for dispersion, grinding and classification, to further improve purity and fineness of finished calcium hydroxide powder.
What if the quicklime raw material is poor?
Crush and screen calcined quicklime to separate overburned and underburned materials. Send normally calcined quicklime with poor activity to Lime Slaker, appropriately raise water-lime ratio and reaction temperature, strengthen stirring intensity of digestion reaction and extend static aging time, so as to maximize digestion efficiency and calcium hydroxide activity.
Why does calcium hydroxide production line classify before grinding?
Modern calcium hydroxide production lines generally adopt advanced pre-classification then grinding process. Calcium hydroxide digested by Lime Slaker is a mixture of qualified finished powder and coarse powder. The front high-efficiency classification equipment directly separates qualified powder, and only coarse powder is sent into calcium hydroxide grinding mill for grinding. It completely solves ineffective grinding and over-grinding problems of traditional process that grinds before classification, significantly reduces system energy consumption, and improves production line efficiency and powder quality.
Which manufacturer supplies good calcium hydroxide production line?
Three professional indicators should be prioritized when selecting calcium hydroxide production line. The first is digestion technology, focusing on stirring efficiency and heat utilization rate of digester. The second is grinding and classification technology, especially whether special material treatment is applied on roller and ring for strong alkaline materials. The last is environmental protection technology, to check whether it meets national standards. If you need to produce calcium hydroxide, Guilin Mining Machinery is your best choice. With 50 years of focus on powder processing, it has profound machinery technology foundation and multiple patented certificates for calcium hydroxide processes. Its GK calcium hydroxide production line adopts two-stage digestion design with compact structure, greatly cutting investment cost for steel structures, and its digestion capacity outperforms traditional 3~7 stage designs. Patented pulse and water mist multi-stage dedusting technology recovers heat to promote digestion while ensuring dedusting effect, nearly zero sewage discharge. Flexible classification and grinding processes build customized production lines to meet production requirements of calcium hydroxide powder of different grades (industrial, environmental protection, food, pharmaceutical, etc.).
Home
Products
About
Call
