Process Study On The Extraction Of Boron From Jinaier Lake Brines Of Xitai

There are many salt lakes in our country,which are abundant with a lot of useful elements,besides the main elements such as potassium,sodium and magnesium,there are also a large number of rare and dispersed elements,such as lithium,boron,rubidium and bromine,iodine,etc.These salt lakes have important exploitation value.Xitaijinar Salt Lake,located in Qinghai province,aboundant with potassium,boron and magnesium,has promising comprehensive utilization prospect.The old brine of Xitaijinar Salt Lake,which has been extracted potassium,is enriched with boron and magnesium.A solvent extraction method was used to extract boron from the old brine of Xitaijinar Salt Lake.By comparing the extraction effect of boron using two monohydric alcohols,the best operating conditions were obtained.In the process of extraction and reverse extraction,the two monohydric alcohol extraction agents have not appeared emulsifying phenomenon,and in the process of reverse extraction,desalted water can be used to extract boron from organic phase,and with preferably reverse extraction effect.But the two monohydric alcohols have high solution loss rate in aqueous solution,and in contrast,isoamyl alcohol has higher.The isoamyl alcohol has unpleasant smell;extensive use of isoamyl alcohol will be harmful to the body.Thus,the two monohydric alcohol extraction agents are not fit for large-scale industrial production of extracting boron.The extraction effect of the two kinds of 1,3-diol on the extracting boron from brine was investigated.Two 1,3-diol alcohols,that are 2-ethyl-1,3-haxanediol(EHD)and 2,2,4-trimethyl-1,3-pentanediol(TMPD)with good extraction effect and easy to be purchased,were used in the contrast experiment,and the optimum operation conditions for extracting are obtained.Using 1,3-diol to extract boron does not need to adjust pH value of soultion,so the operating procedure is simply;the extraction efficiency is high.The extraction efficiency of EHD is lower than that of TMPD,and the reverse extraction efficiency of EHD is inferior to that of TMPD,and easy to lead emulsifying phenomenon.Although TMPD has higher extraction efficiency of boron,it has high price and not economy to use for the boron extracting.In contrast,EHD is more economical and suitable for extracting boron.The key problem in the EHD extracting boron process is to solve emulsification in the reverse extraction process.A large number of experiments show that adding isooctyl alcohol can alleviate the emulsification when using EHD as extraction agent.The extracting method of boron from the Xitaijinaier Salt Lake brine,which use 2-ethyl-1,3-haxanediol and isooctyl alcohol as mixed extractant,sulfonated kerosine as diluting agent,has high extraction efficiency,and better reusablity.The contrast researches have been down on the multilevel cross-flow extraction and the multilevel countercurrent extraction process using theoretical calculation and cascade simulation experiments.The results show that relative to the cross-flow extraction,the countercurrent extraction process is more suitable for industrial production applications,for its organic solvent and diluent can have cyclic utilization,which reduces the cost and has the very high economic benefit.