<p>The purification process of quartz sandstone was studied in this research. Optical microscopy, laser Raman spectroscopy, scanning electron microscopy (SEM), and inductively coupled plasma mass spectrometry (ICP-MS) were employed to analyze the quartz sandstone samples from Egypt. The results indicate that quartz is the dominant mineral in the sandstone, with complex associated minerals. Furthermore, numerous primary and secondary inclusions were observed within the quartz under the microscope. Chemical analysis of the raw material revealed a total impurity element content of 8407.80 <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>. The major impurities include Al (6258.48 <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Ti (1262.03 <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Ca (321.22 <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Fe (287.46 <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), and Na (221.26 <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>). A process flow combining steps such as ultrasonic desliming, magnetic separation, flotation, calcination, and water quenching with acid leaching under different conditions was developed. After secondary acid leaching at 160 <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$^{\circ }\text {C}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> <mtext>C</mtext> </mrow> </math></EquationSource> </InlineEquation>, the impurity content of the sample was reduced to 89.92 <InlineEquation ID="IEq8"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>, with an impurity removal rate of 98.93%. The main impurities were reduced to Al (33.07 <InlineEquation ID="IEq9"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Ti (22.69 <InlineEquation ID="IEq10"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Ca (6.58 <InlineEquation ID="IEq11"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), Fe (15.69 <InlineEquation ID="IEq12"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>), and Na (4.72 <InlineEquation ID="IEq13"> <EquationSource Format="TEX">$\mu g \cdot g^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>μ</mi> <mi>g</mi> <mo>·</mo> <msup> <mi>g</mi> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msup> </mrow> </math></EquationSource> </InlineEquation>). This study provides significant insights into the purification of high-iron, low-grade quartz sandstone. After purification, the purity of low-grade quartz sand reached 99.991% for the first time, and the flotation sand meets the photovoltaic glass raw material standards of GB/T 30984.1-2015 (Fe<InlineEquation ID="IEq14"> <EquationSource Format="TEX">$_2$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>O<InlineEquation ID="IEq15"> <EquationSource Format="TEX">$_3$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq16"> <EquationSource Format="TEX">$\le $</EquationSource> <EquationSource Format="MATHML"><math> <mo>≤</mo> </math></EquationSource> </InlineEquation> 0.015%, TiO<InlineEquation ID="IEq17"> <EquationSource Format="TEX">$_2$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>2</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq18"> <EquationSource Format="TEX">$\le $</EquationSource> <EquationSource Format="MATHML"><math> <mo>≤</mo> </math></EquationSource> </InlineEquation> 0.02%). Additionally, the raw quartz sandstone is widely distributed with large reserves. It offers raw material support for the developing photovoltaic glass industry in North Africa (Xinyi Egypt project) and could drive the development of the local photovoltaic industry.</p>

The Research on the Purification Technology of Low-Grade Quartz Sandstone: A Case Study of Egyptian Quartz Sand

期刊论文
发表日期：

2025年10月11日

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Yue Qiu,
Liting Sun,
Xiaoyong Yang,
Mei Xia,
Zhenhui Hou

摘要

The purification process of quartz sandstone was studied in this research. Optical microscopy, laser Raman spectroscopy, scanning electron microscopy (SEM), and inductively coupled plasma mass spectrometry (ICP-MS) were employed to analyze the quartz sandstone samples from Egypt. The results indicate that quartz is the dominant mineral in the sandstone, with complex associated minerals. Furthermore, numerous primary and secondary inclusions were observed within the quartz under the microscope. Chemical analysis of the raw material revealed a total impurity element content of 8407.80 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ . The major impurities include Al (6258.48 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Ti (1262.03 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Ca (321.22 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Fe (287.46 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), and Na (221.26 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ). A process flow combining steps such as ultrasonic desliming, magnetic separation, flotation, calcination, and water quenching with acid leaching under different conditions was developed. After secondary acid leaching at 160 $^{\circ }\text {C}$ $^{\circ} C$ , the impurity content of the sample was reduced to 89.92 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ , with an impurity removal rate of 98.93%. The main impurities were reduced to Al (33.07 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Ti (22.69 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Ca (6.58 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), Fe (15.69 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ), and Na (4.72 $\mu g \cdot g^{-1}$ $μ g \cdot g^{- 1}$ ). This study provides significant insights into the purification of high-iron, low-grade quartz sandstone. After purification, the purity of low-grade quartz sand reached 99.991% for the first time, and the flotation sand meets the photovoltaic glass raw material standards of GB/T 30984.1-2015 (Fe $_2$ $_{2}$ O $_3$ $_{3}$ $\le $ $\leq$ 0.015%, TiO $_2$ $_{2}$ $\le $ $\leq$ 0.02%). Additionally, the raw quartz sandstone is widely distributed with large reserves. It offers raw material support for the developing photovoltaic glass industry in North Africa (Xinyi Egypt project) and could drive the development of the local photovoltaic industry.