High-purity SiO₂ (quartz powder and quartz grit) and feldspar flux supplied to float glass, container glass, fibreglass, and specialty glass producers in Australia and Asia-Pacific — with pre-shipment Certificate of Analysis on every consignment.
Silicon dioxide (SiO₂) is the primary glass-forming oxide in virtually all commercial glass. At typical melting temperatures of 1400–1600 °C in a continuous tank furnace, SiO₂ forms the three-dimensional amorphous silicate network that gives glass its optical clarity, chemical resistance, and mechanical strength. The purity of the silica raw material — and in particular its iron oxide content — directly determines the colour, transmittance, and market value of the finished glass.
The global glass industry requires silica raw materials with SiO₂ purity of 99.5% or higher for most commercial applications, rising to 99.90–99.99% SiO₂ for specialty and optical glass. Iron oxide (Fe₂O₃) is the most commercially significant impurity: concentrations above 0.03% in the silica feed produce visible green tinting in finished clear glass.
PIME supplies quartz powder (200–1250 mesh) and quartz grit (0.1–0.5 mm) from audited producers in Rajasthan, India. Indian quartz from the Aravalli belt is recognised in global glass supply chains for its combination of high natural SiO₂ purity, consistent particle size, and low contamination — making it a competitive alternative to Australian domestic silica sand for glass manufacturers seeking superior chemistry at scale.
Fe₂O₃ in silica raw material is the glass industry's most closely controlled impurity. Standard clear container glass requires silica with Fe₂O₃ < 0.03–0.05%. Low-iron (optiwhite) float glass for solar panels, architectural glass, and display substrates demands Fe₂O₃ < 0.015% in the silica source. Specialty optical glass requires < 0.005%. PIME offers quartz powder and quartz grit with verified Fe₂O₃ levels matched to each application tier — confirmed by XRF analysis on every production batch.
Glass batch is a carefully proportioned blend of several minerals, each serving a distinct chemical purpose in the melt. Understanding the role of each component helps glass technologists optimise batch cost, melt energy, and finished product quality.
Quartz powder is the primary glass-forming oxide source in specialty glass, fibreglass (E-glass and S-glass), pharmaceutical glass tubing, and optical glass. Its fine particle size (200–1250 mesh, i.e. 75–10 µm) allows rapid, homogeneous dissolution into the glass melt at lower temperatures than coarser silica sand, reducing energy consumption and improving batch-to-melt conversion efficiency.
Finely milled quartz powder is essential in continuous filament fibreglass manufacturing, where batch homogeneity directly affects fibre diameter consistency and mechanical property uniformity. PIME supplies quartz powder in standard grades from 200 mesh (general glass) to 1000–1250 mesh (specialty and fibreglass applications).
Quartz grit is the coarser silica fraction used as the primary silica charge in float glass, container glass, and tableware glass batch. In a continuous tank furnace, the sized grit (typically 0.1–0.5 mm, equivalent to 30–150 mesh) is blended in exact proportions with soda ash (Na₂CO₃), limestone (CaCO₃), and feldspar, then fed as a batch into the furnace inlet.
High SiO₂ purity (99.90%+ for float glass) is critical to maintain precise glass composition. Grain size distribution is equally important: an excessively fine fraction increases surface area and the risk of batch segregation, while coarse outliers can create undissolved silica inclusions ('stones') in the finished glass — a major quality defect in flat glass production.
Feldspar is a multi-functional batch material in glass manufacturing, simultaneously providing Al₂O₃, K₂O (or Na₂O in soda feldspar), and additional SiO₂. The alumina contributed by feldspar is the single most important structural modifier in commercial glass: even at 1–4% Al₂O₃ in the finished glass, it dramatically increases chemical durability (resistance to acids and alkalis), improves mechanical strength, and raises the glass transition temperature.
Potash feldspar is preferred in specialist glass applications where high chemical resistance is required (pharmaceutical glass, laboratory ware, and high-performance container glass). The K₂O it provides also refines the glass texture and improves the thermal shock resistance of the finished product.
Soda feldspar (albite) provides a combined source of Na₂O and Al₂O₃ in glass batch, offering a natural synergy that reduces the need for separate soda ash additions while simultaneously supplying the alumina required for improved glass durability. It melts at a lower temperature than potash feldspar, making it effective in glass systems fired below 1200 °C and in energy-saving glass formulations.
In float glass and container glass batch designs, soda feldspar is increasingly substituted partially for soda ash to deliver Al₂O₃ without the CO₂ emissions associated with soda ash decomposition — a consideration relevant to glass manufacturers managing their scope 1 emissions footprint.
Each glass product family has distinct silica purity and iron oxide requirements. The table below shows typical industry specifications — all grades are available from PIME with matching product data sheets and pre-shipment Certificates of Analysis.
Standard clear float glass for architectural and automotive applications requires silica with controlled iron levels to prevent green tinting. Quartz grit (0.1–0.5 mm) is the predominant silica form used in float furnace batch. Feldspar is added to supply Al₂O₃ (typically 1–2% in finished glass) which improves durability and reduces devitrification risk.
Solar collector panels, display substrates, and architectural 'ultra-clear' glass require near-colourless silica with Fe₂O₃ below 0.015%. This specification demands beneficiated, low-iron quartz grit or powder — PIME's premium low-iron grade meets this threshold, confirmed by atomic absorption spectroscopy on each production lot.
Amber, green, and flint (clear) container glass each has its own iron tolerance. Flint container glass requires the lowest iron silica source. PIME's standard-grade quartz powder (Fe₂O₃ ≤ 0.05%) is well suited for flint container glass, while amber and green formulations accept slightly higher iron and can use standard commercial silica.
E-glass (electrical-grade fibreglass for composites) and S-glass (high-strength structural fibreglass) demand high-purity, finely milled silica for homogeneous melt. Quartz powder at 200–400 mesh is the preferred form. PIME's fibreglass-grade quartz powder meets the SiO₂, Al₂O₃, and iron limits required by major fibreglass manufacturers in Asia-Pacific.
Borosilicate (Pyrex-type) laboratory ware, optical glass, quartz glass tubing, and pharmaceutical primary packaging glass require the highest purity silica. PIME's ultra-high-purity quartz powder and grit (SiO₂ 99.90–99.99%, Fe₂O₃ < 0.010%) can be supplied with full trace element analysis covering Ti, Mn, Cr, Ni, Cu, and Li on request.
Thermal and acoustic insulation glass wool uses a different base glass composition (higher CaO, MgO, Al₂O₃ relative to container glass), but still requires clean silica as the primary glass-forming oxide. PIME's 200 mesh quartz powder is used in mineral wool formulations where controlled SiO₂ contribution and consistent PSD are essential for fibre diameter control during fiberising.
The following specifications represent PIME's standard commercial supply parameters for glass-industry minerals. Values are verified by XRF analysis on production-batch samples prior to shipment. Certificates of Analysis and third-party inspection available on request.
| Parameter | Quartz Powder (200–1000 mesh) |
Quartz Powder (Low-Iron Grade) |
Quartz Grit (Float / Container Glass) |
Potash Feldspar (Glass Flux) |
|---|---|---|---|---|
| SiO₂ (%) | ≥ 99.5 | ≥ 99.7 | 99.90–99.99 | 62–70 |
| Al₂O₃ (%) | ≤ 0.20 | ≤ 0.10 | ≤ 0.05 | 18–22 |
| Fe₂O₃ (%) | ≤ 0.030 | ≤ 0.015 | ≤ 0.010 | ≤ 0.10 |
| TiO₂ (%) | ≤ 0.02 | ≤ 0.01 | ≤ 0.005 | ≤ 0.05 |
| CaO (%) | ≤ 0.05 | ≤ 0.03 | ≤ 0.02 | ≤ 0.5 |
| MgO (%) | ≤ 0.03 | ≤ 0.02 | ≤ 0.01 | ≤ 0.2 |
| K₂O (%) | — | — | — | ≥ 10.0 |
| Na₂O (%) | — | — | — | 3.0–5.0 |
| LOI at 1000 °C (%) | ≤ 0.10 | ≤ 0.10 | ≤ 0.05 | ≤ 0.3 |
| Moisture (%) | ≤ 0.5 | ≤ 0.3 | ≤ 0.2 | ≤ 0.5 |
| Particle Size | 200–1000 mesh (75–14 µm) | 200–600 mesh (75–25 µm) | 0.1–0.5 mm (30–150 mesh) | 200–300 mesh |
| Electrical Conductivity | — | — | ≤ 5 µS/cm | — |
| Whiteness / Brightness | ≥ 92% (ISO 2469) | ≥ 94% (ISO 2469) | — | ≥ 85% |
Ultra-low-iron grades (Fe₂O₃ < 0.010%) with full trace element analysis available on request. Custom particle size distributions and packaging formats negotiable for large-volume supply agreements.
Glass batch quality is non-negotiable. A single off-specification silica shipment can compromise furnace campaigns, introduce inclusions into finished glass, or force costly product downgrades. PIME builds supply reliability and chemistry consistency into every step of the process.
We work exclusively with producers whose beneficiation circuits include magnetic separation, attrition scrubbing, and flotation where required to reach glass-grade iron levels. Fe₂O₃ is tested at the mine, post-beneficiation, and on the final bagged or containerised product before shipment. We do not rely on a single test point — iron control is monitored across the entire production chain.
Every shipment is accompanied by a Certificate of Analysis covering the full oxide suite relevant to glass: SiO₂, Al₂O₃, Fe₂O₃, TiO₂, CaO, MgO, K₂O, Na₂O, and LOI. For quartz grit, electrical conductivity is also reported. Where required for specialty glass applications, trace element analysis (Ti, Mn, Cr, Cu, Ni, Li) is available at additional cost from an accredited NABL laboratory in India.
Glass batch segregation — where fine and coarse particles separate during transport or conveying — is a practical concern that affects melt homogeneity. PIME specifies tightly controlled particle size distributions with maximum passing values at multiple sieve cuts, not just a single mesh designation. This ensures the silica fraction in your batch plant performs consistently from shipment to shipment.
Rajasthan quartz has been supplied to glass manufacturers in Italy, Spain, Germany, China, South Korea, and Southeast Asia for decades. The Aravalli quartzite deposits are recognised for their naturally high SiO₂ (often 99.8–99.95% in the raw ore), low iron, and stable geology — delivering consistency between shipments that is difficult to achieve from vein quartz deposits of variable grade.
We are experienced in the logistics of shipping industrial minerals from Indian west coast ports (Mundra, Hazira, JNPT) to Australian east coast ports (Port Botany, Port of Melbourne, Port of Brisbane). We understand DAFF biosecurity requirements for mineral imports, containerisation standards for bulk mineral bags, and documentation requirements for AusTradeConnect and customs entry — reducing clearance risk for your procurement team.
Standard glass-grade supply is in 20-foot or 40-foot FCL. For new customers or qualification programmes, LCL trial orders from 5 MT are available. For continuous furnace supply, we work with buyers to establish scheduled shipment programmes with rolling orders to buffer against transit time variability and port congestion — typically recommending a 10–12 week forward stock position for Australian glass plants.
Request a Certificate of Analysis from a recent production batch, a sample for qualification, or a commercial supply quote. Our team responds within one business day.