Applied Mineralogy Research Of Quartz Sandstone

Natural quartz sand is a very important non-metallic mineral resource,which has been widely used in many traditional industries such as glass,ceramics,foundry,metallurgy and chemical industry.However,after years of development,these industries have gradually entered a state of equilibrium between supply and demand,and various industrial indicators have been relatively perfect,and it is difficult to make major breakthroughs in a short period of time.It is becoming more and more important to study new fields of application.This paper first summarizes the distribution and geological characteristics of natural quartz sand deposits in China based on previous studies.Secondly,X-ray fluorescence spectroscopy（XRF）,X-ray powder diffraction analysis（XRD）,micro-slice analysis and other mineral detection methods were used to systematically study the mineral composition structure characteristics of natural quartz sand in different producing areas in China.Then,according to the relevant industry（enterprise）standards,the composition and physical and chemical properties of domestic petroleum fracturing proppant and quartz sand for 3D printing were preliminarily discussed,and the comprehensive quality of natural quartz sand used in the two was made by comparative analysis.Evaluation.Finally,the natural quartz sand is used as the matrix to make the color sand,and the related performance of the test color sand is tested and analyzed.Through the above work,the following research results have been mainly achieved:1.Study on petrological characteristics of natural quartz sand（1）Natural quartz sand raw ore chemical composition variation range:Si O₂82.26%～99.56%,Al₂O₃ 0.05%～7.54%,Fe₂O₃ 0.03%～1.42%,Ti O₂ 0.03%～0.40%,Cr₂O₃ 0.02%～0.06%,Ca O 0.04%～1.90%,Mg O 0.02%～0.24%,K₂O 0.03%～5.29%,Na₂O 0.03%～1.54%,P₂O₅ 0.06%～0.21%,SO₃ 0.01%～0.05%.（2）Natural quartz sand minerals are mainly composed of quartz（90%～95%）,at the same time,contain a small amount of feldspar and mica（1%～8%）,and usually also contain traces of heavy minerals（<1%）,such as tourmaline,Zircon,rutile,sphene and some iron minerals.（3）The particle size of natural quartz sand is mainly medium-fine sand（0.125～0.5mm）,which contains less extremely fine sand and coarse sand.The particle size distribution of natural quartz sand particles in some areas is extremely uneven,with coarse sand accounting for 100%and particle size.Mainly 0.5～2mm.Most natural quartz sands have been fully sorted in the process of mineralization,with higher maturity and better sorting properties.（4）The roundness of the natural quartz sand sample is mainly sub-angular to round,and the sphericity is generally-good.Natural quartz sand has a low density,and its bulk density is between 1.31g/cm³～1.64g/cm³;apparent density is between2.410g/cm³～2.539g/cm³.2.Application of natural quartz sand in quartz sand for petroleum fracturing proppant（1）The main chemical composition of quartz sand used in domestic petroleum fracturing proppant varies:Si O₂ 85%～95%;Al₂O₃ 1%～7%;Fe₂O₃ 0.1%～1.3%;K₂O+Na₂O 3%～5%;Ca O+Mg O 0.4%to 0.6%.In addition,it also contains a very small amount of Ti O₂,Cr₂O₃,P₂O₅,SO₃,Mn O₂,and Ba O.（2）Quartz sand for domestic petroleum fracturing proppant is mainly quartz,and contains a small amount to a trace amount of impurity minerals,which are tourmaline minerals,clay minerals and tourmaline in heavy minerals.（3）Quartz sand for domestic petroleum fracturing proppant can be divided into four types according to particle size,which are 20/40,30/50,40/70 and 70/140,respectively,and their market demand share accounts for 53%,4%,20%and 23%,respectively.According to the experimental test,the sphericity of the quartz sand proppant is generally greater than 0.7,and some even reach 0.9;the bulk density（visual density）is 1.59g/cm³ to 1.64g/cm³（2.61g/cm³ to 2.67 g/cm³）.Among the three manufacturers of samples collected,two quartz sand proppants broke between 7%and14%,and the other quartz sand proppant broke more than 16%.（4）Theoretically,the natural quartz sands in LD02、XY03、LL05、ZW10,and TL11 areas meet the requirements for the production of petroleum fracturing proppants.Among them,LD02 and XY03 are suitable for the production of 40/70（0.21～0.42mm）models,LL05、ZW10、TL11 is suitable for the production of 70/140（0.104～0.21mm）model products.Natural quartz sand samples in other regions do not meet production standards in terms of particle size and compressive strength,and further processing is required.3.Application of natural quartz sand in quartz sand for 3D printing（1）In the chemical composition of raw sand（finished product）of quartz sand for domestic 3D printing,the Si O₂ content is 98.032%（98.712%）,and the total content of basic oxides Al₂O₃,Fe₂O₃,Ca O,Mg O,K₂O and Na₂O is 1.137%（0.711%）.The total content of transition metal oxides Fe₂O₃,Ti O₂,Cr₂O₃,and Zr O₂ is 0.32%（0.197%）.（2）The quartz sand used for domestic 3D printing can be divided into two models according to the particle size,which are 50/100 and 100/200 respectively,of which100/200 models occupy a large share of the market.Through experimental tests,the bulk density（finished product）of quartz sand for 3D printing is 1.39 g/cm³（1.34 g/cm³）,the apparent density is 2.64 g/cm³;the acid consumption of raw sand（finished product）is 1.7 m L（1.5m L）;the original sand（finished product）has an angular factor of 1.23（1.22）and the particle shape is between semicircle and circle.（3）After testing and analysis of natural quartz sand samples,it can be known that the natural quartz sand in the ED01 area meets the quality requirements for 3D printing quartz sand in terms of chemical composition,particle size,density and angular factor,and the LD02 and XY03 areas meet the angular factor requirements after further beneficiation processing Can also be produced.4.Research on the application of natural quartz sand in artificial colored sand（1）Among the preparation methods of colored sand,the ceramic colored glaze method is superior,which is characterized by bright colors and good durability.The coloring effect of natural quartz sand is better,and the coloring layer can easily cover the color of the substrate itself.（2）In the coloring process of colored sand,the dry powder method can avoid the phenomenon that the colored sand sticks together before firing into the furnace.The thickness of the colored layer can be controlled by the amount of powder added.（3）The artificial colored sand prepared by the ceramic colored glaze method with natural quartz sand as the matrix has the water resistance,alkali resistance,acid resistance,and thermal stability all meeting the requirements of colored sand,but its preparation process,especially coloring The process needs further improvement.