Resource recovery equipment for roasting with sodium and leaching acid ammonium salt vanadium settling wastewater

Abstract

The invention discloses resource recovery equipment for roasting with sodium and leaching acid ammonium salt vanadium settling wastewater. The equipment comprises an anhydrous sodium sulfate evaporating, crystalizing and separating system, a mother liquor cooling and crystalizing system and an ammonia sulfate evaporating and crystalizing system which are connected in sequence according to the treatment sequence of wastewater, and a programmable logic control system for monitoring the equipment, wherein the anhydrous sodium sulfate evaporating, crystalizing and separating system is used for concentrating and crystalizing wastewater and performing solid-liquid separation to obtain anhydrous sodium sulfate crystal and a first solution; the mother liquor cooling and crystalizing system is used for cooling and crystalizing the first solution and performing solid-liquid separation to obtain a complex salt of sodium sulfate and ammonia sulfate and a second solution; and the ammonia sulfate evaporating and crystalizing system is used for evaporating, concentrating and crystalizing the second solution and performing solid-liquid separation to obtain a mixed ammonia salt of ammonia sulfate and ammonium chloride and a third solution. By adopting the equipment, anhydrous sodium sulfate, ammonia sulfate and condensed water can be crystalized and recovered stepwise from wastewater, and resource recovery of vanadium settling wastewater is realized comprehensively.

Description

technical field [0001] The invention relates to a wastewater treatment device, in particular to a resource treatment device for sodium roasting-leaching-acid ammonium salt precipitation vanadium wastewater. Background technique [0002] At present, the raw materials used in the production of vanadium oxide in the world include vanadium slag obtained from vanadium-containing minerals, vanadium-containing stone coal, spent catalysts, and petroleum cinders. There are two main production processes of vanadium oxide, one is calcification roasting-acid leaching-hydrolysis vanadium precipitation (referred to as lime method); the other process is sodium roasting-leaching-ammonium salt precipitation vanadium (referred to as sodium salt method) , The vanadium products produced by the sodium salt method are of high quality and stable production. [0003] However, the wastewater produced by the sodium salt process is a kind of high ammonia nitrogen, high V (V) or high V (V) and Cr (...

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Problems solved by technology

[0005] The former method is thorough, but the process is long, the investment is large, and the energy consumption is high. Most enterprises cannot afford the high investment and operating costs, and often dilute the discharge after removing vanadium and chromium.

The latter method has a relatively simple process, but cannot effectively recycle the sodium and ammonium salts in the wastewater

Ammonium salt enters sodium sulfate crystals and condensed water in the form of impurities, resulting in high ammonium salt content (6% to 20%) in sodium sulfate products, which cannot be effectively utilized; because the pH of the solution is controlled at 8.0 to 8.5 during evaporation and concentration, the condensed water The content of ammonia nitrogen is high (ammonia 400mg / L~1200mg / L), and the environment is polluted by the release of ammonia during the recycling process

The corresponding wastewater treatment equipment of the above method is also limited in application due to insufficient treatment methods

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