Process for preventing rotary kiln from forming ring

Abstract

The invention relates to a process for preventing a rotary kiln from forming ring, and belongs to the field of the hydro-metallurgy of rare earth. During a production process of high-temperature roasting of rare earth ore concentrate in concentrated sulfuric acid, the concentrated sulfuric acid and the rare earth ore concentrate are roasted in a rotary kiln; and simultaneously, a material feedback hole is formed on a low-temperature section position of the rotary kiln, a material return hole is formed on a high-temperature section of the rotary kiln, and the material feedback hole and the material return hole are connected through a feed delivery pipe outside the rotary kiln; when roasted ore in the rotary kiln moves to the material return hole on the high-temperature section, partial roasted ore enters into the material return hole, and enters into the rotary kiln to mix with an ore acid material after the roasted ore is delivered to the material feedback hole on low-temperature preheating section through the feed delivery pipe, and then is roasted once again. The process has the advantages of being relatively high in operation continuity and controllability, and easy to industrially produce.

Description

technical field [0001] The invention relates to a process method for preventing ring formation in a rotary kiln, which belongs to the field of rare earth hydrometallurgy. technical background [0002] At present, the third-generation sulfuric acid high-temperature intensified roasting process is commonly used in China to decompose rare earth concentrates from Baotou rare earth concentrates. This process has low processing costs, high rare earth decomposition rates, and mature processes. The imbalance of ore-acid ratio and the high temperature of the kiln tail cause the phenomenon of ring formation inside the rotary kiln, which affects the normal production of rare earth concentrate roasting. [0003] The measures mentioned in the post technical training materials for rare earth hydrometallurgy process to prevent ring formation in the rotary kiln during the high-temperature roasting of rare earth concentrates with concentrated sulfuric acid include: checking the acid ore rati...

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Problems solved by technology

[0002] At present, the third-generation sulfuric acid high-temperature intensified roasting process is commonly used in China to decompose rare earth concentrates from Baotou rare earth concentrates. This process has low processing costs, high rare earth decomposition rates, and mature processes. Ore-acid ratio imbalance, high kiln tail temperature and other reasons cause ring formation inside the rotary kiln, which affects the normal production of rare earth concentrate roasting

[0003] The measures mentioned in the post technical training materials for rare earth hydrometallurgy process to prevent ring formation in the rotary kiln during the high-temperature roasting of rare earth concentrates with concentrated sulfuric acid include: checking the acid ore ratio at any time, controlling the roasting temperature at the kiln tail to not be too high, etc., but these methods Difficult to achieve in existing production processes

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