Abstract: Disclosed is a method for digesting a bauxite slurry is disclosed. The method comprises: obtaining a raw bauxite slurry; pre-desilicating the raw bauxite slurry to obtain a pre-desilicated slurry; preheating the pre-desilicated slurry to obtain a dephosphorized slurry; and digesting the dephosphorized slurry to obtain a digested bauxite slurry.

Abstract: A readily soluble alumina and a method for preparing the same involve: mixing an aluminum hydroxide and a sodium aluminate solution to obtain an aluminum hydroxide slurry; performing a high-temperature reaction on the aluminum hydroxide slurry to obtain an alumina hydrate; and performing a low-temperature calcination on the alumina hydrate to obtain a readily soluble alumina.

Abstract: A rail vehicle and a low-vacuum rail vehicle system. The rail vehicle comprises: a ram air inlet, the ram air inlet being provided outside a carriage; a compressor, an air inlet of the compressor being communicated with the ram air inlet; a heat exchanger, a hot-side inlet of the heat exchanger being communicated with an air outlet of the compressor), a hot-side outlet of the heat exchanger being communicated with the inner space of the carriage, and a cold side of the heat exchanger being provided with a refrigerant for heat exchange; and an exhaust valve, a first end of the exhaust valve being provided on the inner side of the carriage, and a second end of the exhaust valve being provided on the outer side of the carriage.