Six Key Stages of Frac Quartz Sand Processing | LZZG

Published: 03/19/2021

Frac quartz sand is a high-strength, high-purity proppant processed from natural quartz sand, and a critical material in oil & gas hydraulic fracturing. Production follows 3 key requirements:

• Purity: SiO₂ content ≥98%, with impurities (iron, aluminum, calcium, etc.) strictly below 0.1% to prevent reactions with fracturing fluid that could block fractures.
• Particle size: Selected by formation permeability, commonly 20/40 mesh (0.425–0.85 mm) or 30/50 mesh (0.3–0.6 mm), with uniform grading to avoid proppant settling or embedding into fracture walls.
• Pre-treatment: Washing, magnetic separation and scrubbing remove mud and mica impurities; scrubbing strips surface attachments via mechanical friction, raising SiO₂ purity by 2%–3%.

LZZG Frac Quartz Sand Plant Consists Of 6 Core Stages

1. Frac Sand Crushing

High-purity quartz sandstone is the main source of frac sand. Quartz sandstone has undergone long-term weathering and denudation. Except for the quartz mineral particles, almost all other minerals in the original rock have been weathered and eroded. At the same time, the quartz particles have extremely high roundness, which are indispensable conditions for the production of frac sand.

Quartz sand passes through crushing equipment to produce frac sand with different diameters. According to different uses, the diameter of frac sand is mostly in the range of 0.1 to 2.0 mm. Most of them are concentrated in the range of 0.4 to 0.8 mm.

2. Frac Sand Screening & Classification

The crushed frac sand needs to be screened with a vibrating screen. It mainly divides the crushed finished products into varieties, and its main production equipment is a vibrating screen. Screening efficiency directly affects production efficiency.

LZZG’s screening machine has the advantages of large processing capacity, high screening efficiency, long life, and other advantages, for customers’ reference.

3. Frac Sand Washing & Scrubbing

After crushing and screening, the frac sand needs to be processed by a sand washing machine and a scrubbing machine. The sand washing machine can remove the impurities covering the surface of the sand and at the same time destroy the water vapor layer covering the sand grains to facilitate dehydration and play a role in efficient sand washing and cleaning.

The scrubbing machine can scrub the dirt and oxidized impurities on the surface of the silica sand to improve the purity of the silica sand material, and the scrubbing efficiency can reach more than 90%.

4. Frac Sand Dewatering

LZZG dewatering screen equipment can remove the moisture in the frac sand material so that it can be stacked in the drying treatment stage for further processing. It can also remove excess mud and other impurities in the material.

Efficient dehydration can reduce fuel consumption in the dry processing stage, reduce water transportation, reduce residual slag, and increase the turbidity of the final sand.

5. Fine Sand Recovery

The main function of the fine sand recovery machine is to clean, dehydrate, and classify the frac sand. It can well recover a large amount of frac sand lost by the sand washing machine in the traditional sand making industry, which improves economic efficiency and reduces the disposal of tailings. The cost and loss of fine sand will cause pollution and damage to the environment.

6. Tailwater & Sludge Treatment

If frac sand production wastewater is discharged directly, it can seriously pollute the environment. The closed-loop sewage treatment system designed and developed by LZZG solves this problem by recycling process water. Under a recycling principle, wastewater is separated into clean sand, mud and water, and dry-discharged solids. This is achieved through a series of stages: screening, cleaning, dewatering, recycling, solid-liquid separation, and sludge dewatering.

Sand and gravel recovery rate stays high, while sewage is purified and recycled to save resources, cut water consumption and meet environmental requirements.

The system mainly consists of sewage treatment pipelines, sewage tanks, clean water tanks, sediment separation equipment, screening equipment, fine sand recovery equipment, dryers, thickeners and filter presses, with the high-efficiency deep cone thickener as a core unit for mud-water concentration.

LZZG Frac Sand Plant Advantages：

1. Equipment is specifically designed for silica sand applications.
2. Drier products reduce storage space and costs.
3. This system recycles more of the water.
4. Final product comes in various sizes that meet different demands.