Research On Properties And Modification Of Nanyang Medical Stone

Medical stone is a kind of medicine stone and also a kind of adsorption mineral.It has many properties of biological activity,adsorption,bidirectional regulation of pH value, dissolution,mineralization and non-toxin.In recent years,as a result of economic development,on the one hand,people's living standards improve,so they attach more and more importance to health;on the other hand,environmental pollution,especially water pollution are becoming serious and the threat to people's healthy living.Medical stone, because of its good adsorption and low prices,is a economical and practical choice of water pollution control,and its dissolution and mineralization properties are of great help to human health.It is therefore the use of Medical stone to produce health products,and through modification to improve the adsorption of inorganic and organic pollutants and bacteria,to enhance its ability of removing water pollutants,to expand the scope of its application and improve the value of its use.This paper studies the Nanyang Medical stone properties of dissolution and bi-directional regulation of pH value.This paper also studies the influence on ammonium adsorption of Nanyang Medical stone which is modified through calcination and by sulfuric acid,sodium hydroxide,HPAM,and some of sodium salt,potassium salt,magnesium salt and ammonium salt as modifiers in ammonium sulfate solution as the adsorbents.In accordance with the changes of ammonium adsorption ratio before and after modification of Medical stone,the paper compares the advantages and disadvantages of these modification methods, sums up the modification rules and determines the best modification means,which provides the basis of comprehensive application for Nanyang Medical stone.Study shows that:Nanyang Medical stone has good dissolution performance and can dissolve out many constant and trace elements such as Si,Al,Fe,Ca,K,Mg,Na,Mn,Zn,B and so on in the water.It also has good performance of bi-directional regulation of pH value in solution,and the rang of regulation△pH is 1～1.5.Along with the increase of amount and extension of time,ammonium adsorption ratio of Nanyang Medical stone increased.The adsorption modes of ammonium for Nanyang Medical stone are both physical adsorption and ion exchange adsorption,and its physical adsorption rate is in line with the Langmuir adsorption rate equation;ion-exchange adsorption is physical adsorption capacity of 8.23 times.Nanyang Medical stone which modified by different modification modifiers have different effects of ammonium adsorption ratio,of which adsorption capacity from maximum to minimum as follows:salt solution＞HPAM＞alkali＞CK＞acid＞calcination(according to the maximum adsorption ratio of each method).Ammonium adsorption ratio of Nanyang Medical stone which is modified by different salt solution is also different.The adsorption capacity from maximum to minimum is:sodium salt＞potassium salt＞CK＞magnesium salt＞ammonium salt(according to the maximum ratio of adsorption).In the experimental range, calcination temperature of Nanyang Medical stone is 300℃and the calcination time is preferably no more than 4h.The most suitable conditions of sulfuric acid modification are: temperature:90℃;modification time:1h;dosage:16.7mL/g;concentration:0.5mol/L.The most suitable conditions of sodium hydroxide modification are:temperature:room temperature;modification time:5h;dosage:41.7mL/g;concentration:2.5mol/L.The most appropriate conditions of HPAM modification are:hydrolysis degree of PAM:30%; hydrolysis time of PAM:3h;HPAM concentration:0.3%(wt%).For Nanyang Medical stone, sodium salt of Na₂SO₄ has the best modification effect and the most appropriate modification conditions are:temperature:room temperature;modification time:0.5h～1h;dosage: 12.5mL/g～25mL/g;concentration:0.5mol/L～1.0mol/L;pH value:7.