【Frontiers in HaiChuan Chemical Technology】Breakthrough achieved in using ferrous chloride produced as a by-product of titanium dioxide to manufacture lithium manganese iron phosphate

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On the 27th of the month, news came from Panzhihua Quanrui Industrial Co., Ltd. The research team led by Pu Zhonghua at this company, in collaboration with relevant domestic institutions, used the high-purity ferrous chloride solution produced by Quanrui Industrial’s titanium dioxide production process based on a non-extraction hydrochloric acid method as the sole iron source. By applying multi-element material metallurgy techniques, they carried out industrial-scale experiments for the preparation of lithium manganese iron phosphate cathode materials via the liquid-phase method using ferrous chloride solutions, and successfully produced lithium manganese iron phosphate (LMFP) cathode materials with excellent properties. According to Pu Zhonghua, the key technical advantages of this experimental project are full circulation and zero emissions; chloride ions and hydrochloric acid are fully reused, while all iron elements are incorporated into the cathode material, with no waste discharged outside. It has been achieved to convert the ferrous chloride produced as a by-product of titanium dioxide production into an iron source for use in new energy cathode materials; the chloride ions are reused in the titanium dioxide production process in the form of hydrochloric acid, thus creating a complete closed loop. This approach enables the transformation from ilmenite to titanium dioxide produced by the hydrochloric acid method, to ferrous chloride, and ultimately to high-quality lithium manganese iron phosphate products. This process technology possesses independent intellectual property rights; there is no waste liquid or solid waste generated throughout the process, which significantly reduces the cost of iron sources and provides a replicable model for the green transformation of the titanium dioxide industry. Test data from a third-party authoritative testing institution show that in this acidic system, the key iron source (recrystallized ferrous chloride solution) contains a high concentration of iron, around 160 g/L; the impurity content is low, manganese is present as a natural by-product, and all other impurities are below the specified limits. The test conclusion is that it meets the requirements for an iron source in lithium iron manganese phosphate ； Lithium iron manganese phosphate cathode material (model MX10): The impurity levels of sodium, potassium, boron, chromium, zinc, nickel, sulfur, etc., are all low; the titanium content is slightly higher due to doping. Its electrochemical properties range from 2.8–4.3 V. The specific capacity on the first discharge at 0.1C is >150 mAh/g, with an efficiency of >92%, while the specific capacity on the first discharge at 1C is >140 mAh/g. Its rate performance at 1C/0.1C is >92%. The phase structure is that of standard olivine. Conclusion: It meets the requirements for battery-grade products. Pu Zhonghua noted that the success of this experiment signifies a strategic shift by Quanrui Industry from “producing titanium dioxide alone” to “co-producing titanium and lithium” using its proprietary non-extraction hydrochloric acid method for titanium dioxide production ； The process technology offers significant value in terms of circular economy; chloride ions are completely recovered in the form of hydrochloric acid and returned to the titanium dioxide production process, resulting in zero loss of this medium ； The iron from ferrous chloride is incorporated into lithium manganese iron phosphate, with no liquid or solid waste discharged. This results in significantly lower product costs and enhanced competitive advantages. In the titanium dioxide production system using hydrochloric acid without an extraction process, multi-element materials are employed to produce high-purity ferrous chloride on a combined basis, thereby replacing high-purity ferrous sulfate, electron-grade iron oxide, and ferrous oxalate as sources of iron. This approach enables the supply of large quantities of a stable source of iron for lithium manganese iron phosphate, allowing the cost of this material’s iron source to be reduced by more than 40%. It is understood that the Panxi region possesses abundant resources of vanadium-titanium magnetite; traditional processing methods only recover titanium and vanadium, leaving large amounts of iron resources to be stored as low-value by-products. Quanrui Industry’s new integrated closed-loop process technology has opened up a completely new industrial chain pathway for vanadium-titanium magnetite in the Panxi region: \"ore → titanium dioxide → ferrous chloride → lithium manganese iron phosphate\". This approach enables the synergistic and high-value utilization of multiple elements such as iron, titanium, chlorine, lithium, and manganese, thus providing a new route for the high-value exploitation of vanadium-titanium magnetite in that area.