Fluorite Mineral Processing Technology: Full Beneficiation Flowsheet from Run-of-Mine Ore to High-Grade Concentrate

24/07/2026

Fluorite Mineral Processing Technology: Full Beneficiation Flowsheet from Run-of-Mine Ore to High-Grade Concentrate

Abstract

Raw run-of-mine (ROM) fluorite generally features low inherent CaF₂ head grade and intimate intergrowth with gangue minerals including quartz, calcite and barite. Crushing and flotation serve as core beneficiation technologies to produce acid-grade, ceramic-grade and metallurgical-grade fluorite concentrates. Advanced composite depressants effectively resolve the global technical bottleneck of fluorite-calcite separation, supporting booming demand from new energy and semiconductor industries for high-purity fluorochemical feedstock. This paper systematically elaborates the full fluorite beneficiation circuit, detailing the technical transformation from crude ROM ore to high-value fluorite products.

1 Overview & Core Principles of Fluorite Beneficiation

1.1 Core Objectives

Fluorite beneficiation targets purification and grade classification: physical and chemical separation methods are deployed to remove gangue, enrich CaF₂, and manufacture standardized fluorite concentrates classified by CaF₂ purity and strict impurity thresholds. Industrial fluorite concentrates fall into three mainstream commercial grades:

Acid-Grade (Chemical-Grade) Fluorite Concentrate

CaF₂ ≥ 97%, SiO₂ ≤ 1.0%. Primary raw material for hydrofluoric acid (HF) and downstream fluorochemical manufacturing.
Ceramic-Grade Fluorite Concentrate

CaF₂ ranging 85%–96%, widely applied in ceramic glaze, glass melting and cement clinker production.
Metallurgical-Grade (Flux-Grade) Fluorite

CaF₂ ranging 70%–85%, used as slag fluidizer in ironmaking and steelmaking to improve slag mobility and boost desulfurization/dephosphorization efficiency.

1.2 Fundamental Design Rule

Beneficiation flowsheet layout is fully customized based on ore mineralogical characteristics, especially mineral dissemination fineness and paragenetic association between fluorite and gangue. Ore pre-beneficiation mineralogical testing + personalized process design is the golden principle for stable fluorite separation performance.

2 Complete Fluorite Beneficiation Flowsheet Breakdown

A standard full-process fluorite concentrator consists of four sequential core sections: Crushing & Screening → Grinding & Classification → Flotation Separation → Thickening, Dewatering & Drying. Among them, flotation is the dominant core technology for manufacturing high-purity acid and ceramic-grade fluorite concentrates.

2.1 Preparation Section: Crushing & Screening

ROM fluorite ore arrives in massive lumps and requires staged size reduction to create qualified feed for grinding. The mature industrial configuration adopts a two-stage crushing + closed-circuit screening circuit:

Primary Crushing (Jaw Crusher)

Reduce bulk ROM ore to particle size below 200–300 mm.
Secondary Crushing (Cone / Impact Crusher)

Further crush coarse fragments to 50–70 mm.
Vibrating Closed-Circuit Screening

Vibrating screens classify crushed material: qualified fine fractions proceed to grinding; oversize coarse particles circulate back to the secondary crusher for re-crushing.

This section delivers uniform particle size feed to stabilize subsequent grinding efficiency and avoid over-grinding slime generation.

2.2 Core Separation Section: Grinding, Classification & Flotation

2.2.1 Grinding & Closed-Circuit Classification

Crushed feed is ground to full mineral liberation fineness (typically -0.074 mm / -200 mesh) to enable efficient flotation separation:

Grinding Unit: Ball mills or rod mills apply impact and attrition forces to fine-grind ore particles.
Classification Unit: Spiral classifiers or hydrocyclones separate mill discharge into two streams: overflow fine liberated pulp for flotation, underflow coarse unliberated sand returned to the mill for regrinding.

Closed-circuit classification balances liberation degree and avoids excessive slime formation that deteriorates flotation selectivity and recovery.

2.2.2 Flotation Separation (Core Beneficiation Unit Operation)

Flotation exploits discrepancies in mineral surface physicochemical properties. Target fluorite particles are selectively hydrophobized by flotation reagents, attach to air bubbles and float to froth layers for separation. Precise pulp and reagent control determines concentrate grade and recovery.

Step 1 Pulp Conditioning & Reagent Addition

Ground pulp is transferred to conditioning tanks to adjust pulp density and add staged flotation reagents in fixed sequence:

Depressants (Core Technical Agent)
- Sodium silicate (water glass): Standard depressant for silicate gangue (quartz); forms hydrophilic film on quartz surfaces to suppress flotation.
- Composite organic depressants (quebracho extract, tannic acid, lignosulfonate): Mandatory for calcite/dolomite-bearing ores. These agents selectively adsorb onto calcium carbonate surfaces to block calcite flotation while retaining fluorite hydrophobicity. Fluorite-calcite separation remains a worldwide classic mineral processing challenge due to identical Ca²⁺ surface active sites.
Collectors

Render fluorite particle surfaces hydrophobic for bubble attachment.
- Traditional agents: Oleic acid, oxidized paraffin soap, low cost but poor solubility under low-temperature pulp conditions with moderate selectivity.
- Modern industrial alternatives: High-efficiency composite fatty acid collectors with superior cold-water adaptability and separation precision, widely adopted in new concentrators.
pH Modifiers

Soda ash (sodium carbonate) is the universal regulator to maintain weakly alkaline pulp (pH 8–10), the optimal window for maximizing depressant and collector performance.

Step 2 Multi-Stage Flotation Circuit Operations

Conditioned pulp enters a tiered flotation circuit including rougher, cleaner and scavenger cells:

Rougher Flotation

High collector dosage and moderate depressant addition float bulk fluorite together with easily-floated gangue to produce rough concentrate. The primary goal is to maximize overall fluorite recovery.
Multi-Stage Cleaner Flotation (3–7 stages standard)

Rough concentrate undergoes repeated re-flotation with incremental low-dose depressants to reject entrained gangue impurities. More cleaning stages deliver higher CaF₂ concentrate grade at the cost of slight single-stage recovery loss.
Scavenger Flotation (1–2 stages)

Rougher tailings enter scavenger cells to recover residual unliberated fluorite, lowering final tailings CaF₂ loss and boosting full-circuit recovery.

2.3 Final Product Processing Section: Thickening, Filtration & Drying

Flotation concentrate is discharged as high-moisture slurry and requires staged dewatering for storage and transportation:

Thickening

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