【Ten Years of Rapid Development in Chemical Equipment】From 2024 to 2025, independently developed semi-hydrate and dihydrate wet phosphoric acid production technologies have driven the transformation and upgrading of the phosphate chemical industry
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Let’s give praise and encouragement to the achievements made in China’s chemical engineering technology and equipment; your participation in discussions is the greatest encouragement. **********************【Ten Years of Progress in Chemical Engineering Equipment】Regular updates and summaries are available; feel free to join the discussions: https://bbs.hcbbs.com/thread-3576046-1-1.html ***************** Recently, the semi-hydrate/dihydrate wet-process phosphoric acid production technology developed by China Wuhuan Engineering Co., Ltd. was included in the first list of advanced and applicable technologies announced by the Ministry of Industry and Information Technology. This technology not only overcomes the key bottlenecks that hinder the development of this industry, but also provides a basis for the green transformation of the phosphate chemicals sector, thanks to impressive results such as a 52% reduction in total energy consumption, a phosphorus recovery rate of 98.5%, and a total phosphorus content in phosphogypsum below 0.5%. Promote the transformation and upgrading of the phosphate chemical industry. The phosphate chemical industry is an important basic industry. However, traditional wet phosphoric acid production technologies face numerous challenges. On the one hand, although China is rich in phosphate rock resources, a large proportion of them are of medium and low grade; traditional technologies have low efficiency in utilizing such phosphate rocks, resulting in resource waste. On the other hand, the high energy consumption and high pollution associated with traditional production methods are significant issues; in particular, the generation and treatment of large amounts of phosphogypsum have become bottlenecks hindering the sustainable development of this industry. According to statistics, about 5 tons of phosphogypsum are produced for every ton of phosphoric acid manufactured. The storage of phosphogypsum not only occupies a large amount of land but also pollutes the environment. Against the backdrop of steady progress toward the \"dual carbon\" goals, the phosphorus chemical industry urgently needs a revolutionary technology that enables efficient use of resources while reducing energy consumption and pollution. Thanks to its years of dedicated efforts in the phosphorus chemicals industry and substantial investment in research and development, China Five Rings has, after over a decade of hard work, successfully developed a semi-hydrate/dihydrate wet-process phosphoric acid production technology with complete intellectual property rights.
Improving the utilization rate of low-grade phosphate ores A key advantage of this technology is that it enhances the efficiency of utilizing low-grade phosphate ores. Through a unique design of the process system and optimization of reaction conditions, the research team ensured full reaction of the otherwise difficult-to-treat low- to medium-grade phosphate rocks, increased their decomposition rate, and expanded the range of applications for phosphate rock resources. This technology also performs excellently in terms of low carbon emissions and energy conservation; compared to traditional dihydrate systems, it reduces overall energy consumption by 52%, while increasing phosphorus recovery rates to over 98%. This means that, when producing the same amount of phosphoric acid, a significant reduction in the consumption of phosphate rock can be achieved, thereby improving the economic efficiency of the enterprise. Phosphoric acid products manufactured using this technology possess excellent quality, enabling them to meet the production requirements of various downstream products such as phosphate fertilizers, feed-grade phosphates, and fine phosphates, thereby providing support for the development and application of such fine phosphates. In terms of phosphogypsum treatment, this technology also has significant advantages. The by-product gypsum generated during the production process has good quality, with a reduced content of water-soluble phosphorus in it, which creates favorable conditions for the harmless treatment of phosphogypsum and its full utilization as a resource. These phosphogypsum can be utilized as a resource by further processing them into building materials, road base materials, and other products; at the same time, they can meet environmental standards for safe storage, thereby reducing potential harm to the environment.
12 sets of wet phosphoric acid production units have been built. During the technology development process, the control of calcium sulfate crystallization is a key challenge. Different crystal forms and particle size distributions directly affect product quality and production efficiency. The R&D team innovatively developed a technique for controlling the metastable hemihydrate crystallization of calcium sulfate. By precisely regulating parameters such as reaction temperature, phosphorus pentoxide concentration, and reaction time, it was possible to enable calcium sulfate to precipitate in the desired hemihydrate crystal form, thereby laying the foundation for subsequent phosphate filtration and recrystallization. Hydrated phase reconstruction and the efficient dissolution and release of intergranular phosphorus are also key areas for technological breakthroughs. The R&D team conducted in-depth studies on the changes in the crystal structure of phosphate rocks during the reaction process as well as the existence state of phosphorus elements. By optimizing the reaction processes and adding specific chemical reagents, they managed to reconstruct the hydrated calcium sulfate crystal phases, overcoming the bottleneck associated with the difficulty of releasing phosphorus from between the crystals in traditional techniques and thereby increasing the efficiency of phosphorus utilization. To further improve reaction efficiency and product quality, the R&D team has also pursued innovations in sulfuric acid dispersion injection and high-position flash evaporation technologies. They employ a dual-circulation high-level flash evaporation technique with sulfuric acid dispersed and injected into the hemihydrate slurry, allowing the sulfuric acid to react more evenly with the phosphate ore and preventing problems of excessive or insufficient local reaction. At the same time, high-position flash evaporation technology can rapidly separate the water and heat generated by the reaction, improving the stability and production efficiency of the reaction system while reducing energy consumption. To date, this technology has been used to build 12 wet phosphoric acid production plants of various scales at home and abroad, with a total annual production capacity of 2.8 million tons. Among them, Yidu Xingfa Chemical Co., Ltd.’s 380,000 tons per year wet phosphoric acid production facility is the largest of its kind in the world – a semi-hydrate/dihydrate wet phosphoric acid plant of this scale. The equipment used is entirely domestically produced, and all technical and economic indicators meet international advanced standards for that period; the facility has also received the **Quality Project Award**. It is estimated that this device can reduce carbon dioxide emissions by 121,000 tons per year, which is equivalent to saving 50,000 tons of standard coal, while also saving around 3.5 million yuan in investment costs. In the international market, this technology has enabled the construction of relevant production facilities in countries such as Tunisia and Egypt that are part of the Belt and Road Initiative, thereby supporting the development of the local phosphate chemical industry. In the future, China’s five-circle framework will further improve the comprehensive utilization rate of phosphogypsum and develop more energy-efficient and environmentally friendly production processes, thereby contributing more to the high-quality and sustainable development of China’s phosphate chemical industry.
The \"technology for producing wet phosphoric acid using the dihydrate method\" developed by the company was officially authorized by the **Intellectual Property Office in 2004, and it won the 10th China Patent Excellence Award in 2008. By utilizing this patented technology, the company has designed and constructed multiple large and medium-sized phosphate production facilities under EPC turnkey contracts in China, thus becoming a true leader in the industry. The image shows the site of the PJA phosphate project in Indonesia. With the advancement of materials and equipment technologies, as well as the strategic demands for energy savings and reduced consumption in manufacturing, it is imperative to develop more advanced semi-aqueous–dihydrate wet phosphoric acid production technologies. Compared with the dihydrate phosphoric acid process, the hemihydrate-dihydrate phosphoric acid process has obvious advantages. First is the advantage of industrial policy. The \"Guidelines for the Development of Key Industrial Common Technologies (2015)\) issued by the Ministry of Industry and Information Technology identifies only \"the transformation of the existing wet phosphoric acid production process using the hemihydrate-dihydrate process\" as a priority area within the chemical industry; it specifies that the use of hemihydrate-dihydrate technology is the direction for the upgrading and transformation of wet phosphoric acid production facilities. The second is the advantage of advanced technology. The semi-hydrate-dihydrate process features low energy consumption, high phosphorus recovery rate, good quality of the resulting acid, and excellent quality of gypsum. Third is the economic advantage. The semi-hydrate-dihydrate process has lower production costs, with the total energy consumption of the facility being approximately 48% of that of the dihydrate phosphate process. Leveraging its many years of experience in phosphate fertilizer design and turnkey projects, Wuhuan Company has carried out extensive work on the development of semi-hydrate–dihydrate phosphoric acid technologies. It holds a patent for the semi-hydrate–dihydrate wet phosphoric acid production system (patent number: ZL 2015 2 0603324.4) as well as proprietary technology related to this process (proprietary technology number: ZYJS050S). The company’s patents and proprietary technologies have addressed the technical risks associated with the enlargement of such devices, provided real-world examples of successfully enlarged devices, and filled the gap in China’s lack of large-scale semi-hydrate-dihydrate phosphoric acid production facilities. While large-scale construction of the “836 Project” was still underway in China, Wuhuan Company’s phosphorus chemical technology team had already been working intensively in areas such as hemihydrate and dihydrate phosphoric acid for a long time. The company has established a laboratory evaluation system for producing phosphoric acid from phosphate rocks, and has a dedicated technical team specialized in the testing and research of phosphate rocks to carry out basic research such as evaluations of phosphate rocks. In the development of the phosphate chemical industry, Wuhuan Company has formulated a forward-looking strategy for the development of its industrial and technological chains, and has carried out meticulous management with an entrepreneurial approach. Guo Guoqing, the chief engineer of Wuhuan Company, explained that the company follows a development model based on the hierarchical utilization of phosphoric acid in its semi-hydrated and dihydrated forms, by adding further processed products such as phosphates and high-end phosphorus polymers. This approach helps to make use of the production capacity for wet-process phosphoric acid and purified phosphoric acid from upstream sources, thereby improving the industrial chain that includes minerals, fertilizers, salts, and high-end water-soluble fertilizers.
Green Governance: The Rebirth of Phosphogypsum. Green is the foundation of high-quality development. Wuhuan Company is located on the banks of the Yangtze River; it bears the responsibility of protecting this river while also striving for high-quality development. In the field of energy and chemical engineering, engineers focus not only on finding temporary solutions to reduce emissions, but also on addressing the root causes of pollution. The Yangtze River’s sighs were once hidden in the turbid waves of the “River of Milk”. Phosphogypsum – this tens of millions of tons worth of \"ecological obstacle\" each year represents the ultimate challenge standing between the phosphorus chemical industry and a healthy environment. Wuhuan Company’s breakthrough lies in molecular-level blades. Wang Xin, the project manager for Chuxing Chemical’s phosphogypsum washing, purification and harmless treatment project, told reporters that Wuhuan Company developed a unique technical approach based on \"graded purification + targeted modification.\" This approach led to the creation of the first industrial integrated system that combines flotation with multi-stage counter-current washing and functional modification, thereby activating the properties of the gypsum. The entire process for making phosphogypsum harmless allows for the reduction of water-soluble phosphorus and fluoride levels in this material through recovery and modified solidification; at the same time, water-soluble phosphorus is recovered, enabling the treated phosphogypsum to be reused as a resource or stored safely.
The Quest for Blue Oceans: The Aspirations of Pioneers. A husband’s ambitions span the world; even ten thousand miles still seem like nothing in comparison. Since the 1990s, Wuhuan Company has been looking toward the \"blue ocean\" and attempting to expand its operations overseas. The proposal of the Belt and Road Initiative has enabled the company’s engineering expertise and innovative technologies in the phosphorus chemicals sector to make their way onto the global stage. Leveraging its outstanding achievements and strong reputation in the field of design and construction of domestic phosphorus chemical plants, Wuhuan Company demonstrates strong competitiveness in international bidding. Its overseas presence has expanded rapidly: it has successfully undertaken a number of internationally significant EPC turnkey projects in the phosphorus chemicals sector, including those in Tunisia, Pakistan, Indonesia’s PJA and PKG projects, as well as Egypt’s NCIC project. A large number of projects have been successfully completed and are operating stably, with their excellent quality winning widespread praise from international clients and peers. The successful implementation of the Tunis project represents a key milestone in Wuhuan Company’s journey toward internationalization. According to Xu Jinqiao, who was the project’s deputy manager at the time, this project was not only Wuhuan Company’s first overseas EPC contract for phosphorus chemical manufacturing that made use of entirely proprietary intellectual property, but it also marked the large-scale export of its advanced key technologies in phosphorus chemistry. In Tunisia, which is rich in phosphorus resources, the project has attracted international attention since its inception. Just 3 months after starting operation, the facility passed the performance assessment outright, thanks to its excellent product quality and outstanding performance in terms of raw material and energy consumption, all of which exceeded the requirements specified in the contract.
Give praise and encouragement to the achievements made in China’s chemical technology and equipment sector