Acid grade fluorspar 97% fluorite uses

Maohe Import and Export (Tianjin) Co., Ltd is Specialized In Fluorspar Mining, Processing And Trading of Mongolia origin. We have mine direct supply of fluorite CaF2 ranging from 70% to 99%.

Acid-grade fluorspar (minimum CaF₂ 97%) serves as the fundamental feedstock for the fluorochemical industry. It reacts with concentrated sulphuric acid to produce anhydrous hydrogen fluoride (AHF).

Our Typical certificate of analysis is as follows:

FAQ: What are the Impacts of Impurities on HF Reactor Corrosion & HF Yield?

Impurities present in acid-grade fluorspar reduce HF yield and accelerate corrosion of HF reactors via two primary mechanisms: consuming available fluorine, forming highly corrosive by-products, and destabilizing reaction conditions.

Core Mechanisms

Accelerated Corrosion

Moisture (critical hazard), silica (forming SiF₄ and H₂SiF₆), sulphides (generating SO₂ and acid mist), and metallic impurities collectively break down the passive protective film on metal surfaces, triggering localized pitting corrosion and stress corrosion cracking.

Reduced Process Yield

Side reactions between impurities and produced HF directly cut the output of gaseous hydrogen fluoride. Inconsistent feed composition caused by impurities also leads to incomplete fluorspar conversion, further lowering practical yield.

Detailed Impacts of Key Impurities

Moisture (H₂O)

Though not a lattice impurity of fluorspar, moisture is commonly entrained in raw ore. Under high-temperature acidic conditions, rapid vaporisation causes material splashing and disturbs sulphuric acid dosing ratios. It is the primary contributor to accelerated reactor corrosion by disrupting metal passivation and promoting acid mist formation, which intensifies corrosion across piping networks.

Silica (SiO₂)

Silica reacts with generated HF via the side reaction: SiO₂ + 4HF → SiF₄↑ + 2H₂O This directly consumes HF and diminishes target yield. The formed silicon tetrafluoride hydrolyses in humid environments to produce fluorosilicic acid (H₂SiF₆), a highly corrosive substance prone to condensation and blockage in low-temperature sections. Deposits alter gas flow distribution and aggravate erosion-corrosion.

Sulphides & Carbonates

Upon thermal decomposition, these impurities release SO₂, CO₂ and sulphuric acid mist. The resulting strongly oxidising acidic atmosphere accelerates corrosion of carbon steel and low-alloy steel reactor shells. Voluminous gas generation also triggers operating pressure fluctuations, disturbing reaction equilibrium.

Heavy Metals (Arsenic, Lead, etc.)

These form volatile fluorides such as AsF₃. While they do not cause severe direct reactor corrosion, they contaminate crude HF and increase rectification load, undermining overall system stability. Certain metallic ions may also catalyse undesirable side reactions.

Industrial Consequences

Yield Performance

Every 1% increase in SiO₂ content reduces theoretical HF yield by approximately 0.5%–0.8% due to HF consumption. Inconsistent feed quality induced by impurities can trigger an additional 2%–5% loss in practical conversion efficiency.

Equipment Integrity

Raw materials with elevated impurities narrow the operable temperature window. This raises risks of ring formation and material caking on reactor walls, resulting in local overheating, severe corrosion and shortened service life of rotary kilns or HF reactors.

Acid-grade fluorspar is industrially specified with minimum CaF₂ content of 97%. Strict control of SiO₂ and other impurities is required to balance raw material costs, equipment maintenance expenditure and yield losses.