Ammonium Chloride
Ammonium chloride (NH₄Cl), commonly known as electrolytic salt or salt sand, is an important inorganic chemical raw material widely used in agricultural fertilizers, electroplating, pharmaceuticals, food additives, battery manufacturing, and many other fields. Its purity, particle size, and moisture content directly determine its application efficiency. Tianli specializes in the refined production of ammonium chloride, focusing on optimizing three core processes: MVR evaporation, OSLO cold crystallization, and fluid bed drying. Leveraging advanced technology, we create high-purity, low-energy-consumption, and environmentally friendly ammonium chloride products to comprehensively meet the stringent production needs of various industries and contribute to high-quality industrial development
I. Core Properties of Ammonium Chloride
Ammonium chloride is white crystalline powder or granules with the molecular formula NH₄Cl, relative molecular mass of 53.49, density of 1.527 g/cm³, and melting point of 337.8℃ (decomposes). It is odorless, salty and cool in taste, with strong moisture absorption ability. It tends to absorb moisture and agglomerate when exposed to air. Its aqueous solution is weakly acidic, and its solubility varies significantly with temperature: 29.4 g/100 g water at 0℃, and 77.3 g/100 g water at 100℃. This characteristic is the core basis for the process design of the MVR evaporation and OSLO cold crystallization sections. Ammonium chloride is stable at room temperature, decomposing into ammonia and hydrogen chloride above 337.8℃. It is readily soluble in water but sparingly soluble in organic solvents. The raw material is widely available and suitable for large-scale production.
II. Core Process Flow Introduction
(I) MVR Evaporation + OSLO Cold Crystallization Section: Energy-Saving Concentration, Precise Crystal Control
The integrated MVR (Mechanical Vapor Recompression) evaporation and OSLO (Optical Oxide Loop) cold crystallization process is core component of ammonium chloride production. Its main purpose is to concentrate the feed solution through energy-efficient evaporation, followed by precise crystallization to precipitate crystals, balancing energy consumption control with product particle size uniformity and adapting to the solubility characteristics of ammonium chloride. Tianli utilizes forced-circulation MVR evaporation system paired with an OSLO cold crystallizer to achieve integrated high-efficiency concentration and precise crystallization.
The process flow follows the logic of pretreatment - MVR evaporation and concentration - OSLO cold crystallization - solid-liquid separation - mother liquor circulation: the feed solution undergoes pH adjustment, scale inhibition treatment, and filtration purification to remove impurities before entering the forced-circulation evaporator. Secondary vapor is pressurized and heated by a steam compressor, circulating as a heat source, eliminating the need for large-scale replenishment of live steam. The negative pressure within the evaporator controls the evaporation temperature at 70-85℃ to prevent ammonium chloride decomposition. The concentrated saturated liquid is fed into the OSLO cold crystallizer and cooled to 25-30℃ through a gradient. Taking advantage of the characteristic that the solubility of ammonium chloride decreases significantly with decreasing temperature, the crystals are induced to grow slowly. The crystallizer is then used to screen crystals with uniform particle size. After centrifugation, wet ammonium chloride crystals are obtained. The mother liquor is returned to the evaporation system for recycling, and the raw material utilization rate is over 98%
(II) Fluid Bed Drying Section: High-Efficiency Dehydration and Stable Formation
The fluid bed drying section handles the wet ammonium chloride crystals after cold crystallization. Its core task is to remove free moisture from the crystal surface, ensuring the moisture content meets the GB/T 2946-2018 standard (≤0.5%), while maintaining the integrity of the crystal morphology and preventing agglomeration, thus improving product storage stability and application adaptability.
Tianli offers two drying systems of internally heated fluid bed dryer and steam rotary dryer. Both systems incorporate heat exchange tubes for heating and drying the material. The wet ammonium chloride crystals enter the dryer via a conveying device, where they directly contact the heat exchange tubes for heat exchange, completing the drying process and significantly reducing heat loss.
The dried ammonium chloride crystals are then cooled, conveyed, and screened for impurity removal, ultimately yielding the finished ammonium chloride product. The drying exhaust gas undergoes two-stage dust removal treatment—a cyclone dust collector and a wet scrubber—before being discharged in compliance with standards, achieving clean production.
III. Core Technological Advantages
1. Energy-efficient and cost-controllable: MVR evaporation recovers secondary vapor with a latent heat recovery rate exceeding 90%, saving over 55% energy compared to traditional multi-effect evaporation; OSLO cold crystallization utilizes temperature gradient control for crystal growth, requiring no additional energy consumption, significantly reducing overall energy consumption and substantially improving enterprise efficiency.
2. The materials directly contact the heat exchange tubes, facilitating heat exchange and greatly reducing heat loss, lowering steam consumption by 30%.
3. The increased number of internal heat exchange tubes reduces the demand for drying hot air in the drying system, resulting in a smaller footprint for the main equipment and a smaller exhaust gas dust removal system, significantly reducing civil engineering and equipment investment.
4. High-quality products with uniform particle size: OSLO cold crystallization precisely controls crystal growth rate. Combined with graded screening, the product has uniform particle size, complete crystal form, purity ≥99.5%, stable moisture content, and no impurity residue, adapting to various specifications across multiple fields, with quality far exceeding industry standards.
5. Green and environmentally friendly, safe and stable. The closed-loop process achieves mother liquor circulation, with no wastewater discharge; the entire process is sealed with two-stage dust removal, ensuring dust emissions meet standards; intelligent temperature control and pressure monitoring systems eliminate potential hazards such as ammonium chloride decomposition and equipment leaks, achieving green and safe production.
6. Intelligent, convenient, and flexible. The fully automatic PLC control system monitors key parameters in real time, precisely adjusts the process, adapts to different raw material concentrations and product specifications, is easy to operate, highly stable, reduces labor costs, and improves production efficiency.
We empower quality with technology and create value with expertise. Based on the characteristics of ammonium chloride, our company has deeply cultivated core technologies of MVR evaporation + OSLO cold crystallization and fluid bed drying, providing high-quality ammonium chloride products and one-stop solutions for various industries, working hand in hand with customers to promote industrial upgrading and achieve mutual benefit and win-win results.