Device and treatment process for efficiently dealkalizing red mud in aluminum oxide production

Abstract

The invention discloses a device for efficiently dealkalizing red mud in aluminum oxide production, which comprises a settling end washing tank, a dealkalizing plate-and-frame filter press, a reaction tank and a plate-and-frame filter press, an underflow pump is mounted on a connecting pipeline of the settling end washing tank and the dealkalizing plate-and-frame filter press, a slurrying pump and a red mud discharge diaphragm pump are connected in front of the reaction tank, and the plate-and-frame filter press is mounted in the reaction tank. An outlet of the red mud discharge diaphragm pump is communicated with the plate-and-frame filter press; an outlet of the dealkalization plate-and-frame filter press is communicated with an inlet of the reaction tank, and the inlet of the reaction tank is communicated with the dilute nitric acid tank; during treatment, dilute nitric acid is added into the reaction tank, nitric acid, red mud and red mud washing water are mixed and stirred, sodium oxide in nitric acid and red mud reacts to generate sodium nitrate, sodium nitrate is recycled and enters an aluminum oxide production system to react with pyrite in ore, and the effect of ore desulfurization is achieved instead of a desulfurizing agent. The system is reasonable in layout, has the characteristics of online dealkalization, simple process and high dealkalization rate, and not only relieves the environmental protection pressure of enterprises, but also achieves the purposes of energy conservation and emission reduction.

Description

technical field [0001] The invention relates to the technical field of comprehensive treatment of red mud, in particular to a device and a treatment process for efficient dealkalization of red mud in alumina production. Background technique [0002] Red mud is the largest waste produced in the alumina production process, and also the biggest source of pollution in alumina plants. Because of the difference in production methods and bauxite grades, about 0.5-2.0 tons of red mud is produced for every ton of alumina produced. In recent years, the domestic alumina production capacity has continued to grow, and the current operating capacity has exceeded 80 million tons, resulting in a significant drop in the grade of bauxite available in the domestic market in recent years. The energy consumption and alkali consumption increase rapidly, and at the same time, a large amount of high-alkali red mud is produced. According to estimates, the red mud piled in the red mud yard exceeds 10...

Images