Method for preparing sodium stannate by utilizing tin-removed wastewater

Abstract

The invention relates to the sewage treatment technology and in particular relates to a method for preparing sodium stannate by utilizing tin-removed wastewater. The method for preparing sodium stannate by utilizing tin-removed wastewater comprises the following steps of: uniformly mixing tin paste, strong base and water to form a blank material; controlling the temperature to 90 DEG C to 600 DEG C, sintering the blank material for 2-4 hours and forming dry materials after cooling and crushing the blank material; mixing the dry materials with water to form first lixivium, stirring and reacting the first lixivium; carrying out solid-liquid separation on the first lixivium to obtain first filtrate and first sediment; evaporating, concentrating, crystallizing and cleaning the first filtrate to obtain a sodium stannate crude product; and drying the sodium stannate crude product to obtain the sodium stannate product. According to the method for preparing sodium stannate by utilizing tin-removed wastewater disclosed by the invention, the gentle preparation conditions are utilized for greatly reducing the roasting temperature of the existing process, greatly reducing the energy consumption and simplifying the leaching process. Moreover, the thin leaching rate is improved, the economic benefits are remarkable and the development prospect is good.

Description

technical field [0001] The invention relates to sewage treatment technology, in particular to a method for the treatment and recycling of circuit board tin stripping wastewater. Background technique [0002] In the circuit board processing process, the etching operation of the circuit board is an important part of the circuit board processing, and the circuit needs to be effectively protected before etching. The etching of the circuit board is divided into two processes: acid etching and alkaline etching. The acid etching is protected by ink, and the alkaline etching is protected by a tin layer. After the alkaline etching of the circuit board, the protective tin layer needs to be removed. The general tin stripping solution is nitric acid solution, equipped with ferric nitrate, nitric acid stabilizer and copper corrosion inhibitor. When the amount of tin in the tin stripping solution reaches a certain concentration, the tin stripping ability decreases, so it is scrapped, an...

AI Technical Summary

Problems solved by technology

This treatment method has serious disadvantages. On the one hand, the precipitated alkali slag is used as the raw material for pyrometallurgy, and the recycling rate of valuable metals is low, resulting in serious waste, and there is also a serious risk of secondary pollution.

[0013] In some processes for treating tin stripping wastewater, the roasting temperature is higher (up to 850-950 ° C), and the reaction time is longer (2.5-5 hours), which will inevitably greatly increase energy consumption, not only increase costs, but also not conducive to environmental protection.

Images