Determination Of Aluminum Content In Bauxite By EDXRF Method

To this day,bauxite has been the main raw materials for producing aluminium oxide as well as aluminium metallicum,Obviously,its application is widely acknowledged in the production of agriculture and industry.Also,the daily products of residence are the same.In the last decade,the development of aluminum industry has increased at a high speed and aluminum products are applied in different areas of life,thus,the society has an increasing demand for bauxite.However,China has been known for the large variety of types of bauxite resource and different ranges of various quality,in term of technical requirement of the aluminum industry,it has adopted strictly different processes on different types of bauxite.If it were done in that way,it could lead to disastrous processing which needs a lot of investment.Also,it will cause high energy consumption but sadly,the quality will be bad.That is the reason why it is necessary to conduct accurate analysis of aluminum in bauxite before the process of refining as it is tightly connected with economic profitibility and the healthy development in the aluminum industry.In the last decade,as the science and technology develops steadily in our country,the analysis technology of x-ray fluorescence spectrometry(XRF)has been sidely applied in the files of qualitative and quantitative analysis of various elements in substances.In fact,the x-ray fluorescence spectrometry is categorized in Wavelength Dispersive X-ray Fluorescence(WDXRF)as well as EDXRF which is known as Energy Dispersive X-ray Fluorescence.These methods are widely applied in fields of machine manufacturing,minerals and metallurgy,food safety,geographical conditions,medical research,biological science and more areas.The reason is because its analysis circle is very short which means that little investment would be inquired.Besides,the method of operation is simple and high accuracy can be guaranteed.The qualitative analysis and quantitative analysis of aluminum element mainly includes two major methods.These methods are categorized as the following,such as gravimetric method,titration,spectrophotometry,Inductively coupled plasma atomic emission spectroscopy(ICP-AES),X-ray fluorescence which is known as XRF.In fact,chemical analysis method is well-known for its accurate result but it tends to be avoided because the process of operation is quite complicated and the period of time needed for analysis period is too long.On the contrary,the spectrophotometry is known to be easily affected by the condition of the sample,the operation method and other factors,thus,its accuracy tends to be lower.Meanwhile,the ICP-AES and WDXRF methods require to use very sophisticated and costly instruments from the laboratory,thus,its economic investment is considered to be too much.However,the EDXRF method in terms of economic interests,it will be more preferred.The reason is because the sample processing is simple,it has high efficiency and fast speed,instruments are small and portable which means very economic.But,in terms of analyzing light elements(Z<20),because of the fluorescence yield of light elements is quite low,the characteristic x-rays have low energy,and it is similar to the energy of other light elements K-line spectrum,it results in the limitation of the EDXRF method in analysing light aluminum.In order to solve the above problems,this paper is proposing a new method of applying energy dispersive X-ray fluorescence spectrometry(EDXRF)to test the content of aluminum in bauxite.Indirect measurement is used,In this method,light element aluminum should be converted into heavy element silver(silver chloride precipitation)after conducting a series of chemical reactions.The precipitation is made into a round sample,and the content of silver elements in the sample is determined by using the EDXRF spectrometer,Based on the chemical formula of the product,the content of aluminum element in the sample will be calculated through the chemical quantity ratio of aluminum to silver.This article also explores the optimal excitation conditions of silver element.Through the calculation of the peak-to-back ratio of the characteristic spectrum of silver element and the drawing of the relation curve between it and the excitation condition,it is calculated that the optimal tube voltage of silver element is 32 k V,and the best tube current is 12μА.The content of aluminum in bauxite was measured at 29.26% under optimum excitation conditions,Meanwhile,the relative standard deviation is 0.25%,The detection result of the melting chip method is 29.57%and the relative error is 1.05%.Explain that this method is highly accurate,The quantitative analysis of aluminum elements in bauxite by EDXRF method is realized,which is helpful in providing new ideas for the analysis of other light elements.