Study Of Impurity Elements:Sodium,Calcium,Barium,Phosphorus,Sulfur And Lead Inindustrial Barium Sulfate And Barium In Barium Dregs

1,The content and species information of impurity elements is very important to barium sulfate as medical radiocontrast agent,plastic or paint filler.With the help of ultrasonic,this experiment leached different industrial barium sulfate samplesby water and acid respectively.The concentration of sodium,calcium,barium,phosphorus and sulfurin the leached solution above was determined by inductively coupled plasma emission spectrometry?ICP-OES?,and compared the differences of elements concentration in two kinds of leaching solution,and thentook the above results contrast to the pure barium sulfate.At last,combined with the manufacturing technique of industrial barium sulfate,the species of sodium,calcium,barium and phosphorus can be confirmed.By adding Bi³⁺ and Ba²⁺ to water leached solution,and compared the change of sulfur concentration,the experiment can confirm the species of sulfur.In theexperiment,the optimum condition of water leaching:the solid-liquid ratio was 0.5000 g:14.0 mL,the ultrasonic oscillation time was 30 min,the temperature was 55?;the optimum condition of acid leaching:the solid-liquid ratio was 0.5000 g:14.0 mL,0.3 mol·L-1 nitric acid,the ultrasonic oscillation time was 25 min,the temperature was 35?.The results showed that impurity elements attached to barium sulfate surface exist in multiple species,such as sodium exists in the species of water-soluble sodium salt;sulfur exists in the species of water-soluble sulfate and sulfide,meanwhile,sulfur also exists in the species of calcium sulfate slightly;phosphorus exists in the species of water-soluble phosphate,but the most of phosphorus exists in the species of acid-soluble barium phosphate and calcium phosphate.However,barium phosphate will be dissolved by acid solution and the Ba²⁺ is poisonous.2,According to barite barium sulfate as raw materials produced by mirabilite method,the lead in the industrial barium sulfate is in the form of PbS.Firstly,ultrasonic oscillation was assisted to acid leaching of PbS in industrial barium sulfate,The leaching agent was 6 mol·L-1 nitric acid,added 1.00×104?g·mL-1 Ba²⁺ to inhibite barium sulfate release SO₄^2- due to acid effect,avoided the Pb?II?form a kind of precipitation that difficult to dissolve in acid.This paper shows when the coexisting mass concentration of Ba was 3300 times larger than the Pb,there was a relative error of more than-5%caused by the determination of lead with ICP-OES directly.In order to eliminate the interference of Ba?II?to lead in the acid leached solution,0.2 g of strongly acidic cation exchange fiber?SACEF?was used as solid phase extractant,adjusted the pH value of leached solution for five,then Pb and EDTA were synthesised to a kind of complex anions what can not be extracted by SACEF,but Ba?II?would be extracted by SACEF because of Ba?II?can not synthesis complex anions with EDTA,ultimately,the Ba???and lead were be separated and detected by ICP-OES successfully.The lower limit of quantification?10 sc?for lead was 2.90×10-3 ?g·mL-1 in this method.Recovery rate for simulation experiment of PbS in barium sulfate between 95.3%?102%,and the relative standard deviation?RSD,n=5?was less than or equal to 5.1%.The recovery rate for determination of lead in actual sample and simulated sample in the range of 94.8%?106%,and the relative standard deviation?RSD,n=5?was less than or equal to 4.1%.3,Have analyzed barium drags that provided by a barium sulfate factory.With the help of ultrasonic,the barium drags was leached by water and acid respectively,and the determination of barium,sulfur and silicon was completed by ICP-OES.According to compare the concentration of Ba???between the two kinds of leaching solution,associated with the actual production process,the species of barium in the sample was determined.The results shows that the part of barium in drags was existed in the species of BaS,BaSO₃,BaCO₃ and BaSiO₃,and the other barium was existed in the species of BaSO₄.The optimum condition of water leaching:the solid-liquid ratio was 0.5000 g:15.0 mL,the ultrasonic oscillation time was 20 min,the temperature was 30?;the optimum condition of acid leaching:0.50 mol·L-1 HCl,the other conditions were the same as the water leaching.And the water leaching solution and the acid leaching solution should be diluted 200 times and 400 times respectively.