Preparation Of Flower-like β-FeOOH Particles With Pickle Liquor

With the development of science and technology, the application range of the steel increasingly expands and the demand of the steel increases. In order to ensure the cleaning of the iron and steel surface, its surface was dealt with hydrochloric acid, sulfuric acid, nitric acid or mixed acid. Thus, a large amount of pickle liquor was produced. The acidity of pickling waste is strong and there is a great amount of Fe2+. If it can not be properly dealt, pickle liquor will become a potential danger to rivers, lakes and soil. It may even bring bad effects to human’s health. On the other hand, the impertinent discharge will cause great waste of resources. Our lab has been engaging in researching the synthesis and mechanism of the iron oxide in solution. We have accumulated some experience in preparation, characterization and mechanism research. This paper aims at using (hydrochloric acid) pickle liquor to produce P-FeOOH. It is well known that P-FeOOH is an important chemical raw material, and it is widely used in fine ceramics, catalysis and pigment etc. If high quality P-FeOOH can be prepared by using pickle liquor as raw material, it must be of both important theoretical significance and the practical application value.The main research work and results are summarized as follows:(1) The reaction system with pickle liquor-urea was built by using boiling reflux method to prepare chrysanthemum-shaped P-FeOOH micro-nano structure. The influence of the initial pH value, the mole ratio of Fe (II)/Fe(III), the dosage of urea, reaction time on the formation of flower-like p-FeOOH were studied in detail. The best reaction condition was found in the above system. That is, pH=0.8, the mole ratio of Fe (II)/Fe (III)=2:1, the urea dosage is 0.75 mol/L and the reaction time is 40 min.(2) By researching induced factors of flower-like structure and monitoring the growth process of the crystal, we found that the synergy of Al3+ and urea is the main factor of formation of flower-like structure. The experimental results indicated that the growth of P-FeOOH crystals follows the second gathered growth mechanism.(3) The effect of some additives such as ethylene glycol, glycerin, n-butanol, polyethylene glycol, glucose on the formation of flower-like β-FeOOH was investigated. The results show that the flower-like β-FeOOH particles can be obtained in the glycol system. The best preparation condition is:Fe3+concentration of 0.16 mol/L, the Fe2+ concentration of 0.2 mol/L, the ethylene glycol volume of 10 ml, pH=0.5 and the reaction time of 40 min.(4) The function of β-FeOOH on the adsorption of Cr(VI) and degradation of the EBT were initially studied. The results showed that the chrysanthemum-shaped β-FeOOH shows better adsorption on Cr(VI) and light catalytic performance on the EBT.