Analysis of lithium ore dressing technology and key equipment

As the core raw material of the new energy industry, lithium has attracted much attention for its efficient extraction technology. Lithium ore dressing process is a key link in the development and utilization of lithium resources. Its core lies in the efficient separation of lithium minerals and gangue by physical or chemical methods. This article will systematically analyze the lithium ore dressing process and the main equipment configuration.

1. Lithium ore dressing process

The typical spodumene dressing process includes four core links: crushing and screening, grinding and classification, flotation separation, and dehydration and drying. The raw ore is first coarsely crushed by a jaw crusher to reduce the ore particle size to below 150mm, and then crushed to 30mm by a cone crusher. The vibrating screen is pre-screened at this stage to ensure that the qualified particle size ore enters the subsequent process. The grinding process adopts a two-stage closed-circuit process. The ball mill and the spiral classifier cooperate to grind the ore to a fineness of -0.074mm, accounting for 65%-75%, to meet the flotation requirements.

The flotation process adopts the classic process of "one coarse, two sweeps and three fines". By adding NaOH to adjust the pH of the slurry to 10-11, combined with fatty acid collectors and lignin inhibitors, mica and other impurities are floated out first, and then spodumene concentrate is selected. For lithium mica ore, cationic collectors are required for reverse flotation. In the dehydration stage, the concentrate concentration is increased to more than 50% by a high-efficiency concentrator, and then dried to a moisture content of less than 8% by a ceramic filter.

2. Analysis of core equipment technology

Crushing equipment: Jaw crushers are the first choice for coarse crushing due to their high crushing ratio (4-6). Hydraulic cone crushers achieve efficient medium crushing through the principle of lamination crushing, which reduces energy consumption by 15%-20% compared with traditional equipment.

Grinding equipment: Large ball mills (Φ3.6×6m) and hydrocyclones form a closed-circuit system, which increases grinding efficiency by 30%. Vertical mills, which have emerged in recent years, have shown advantages in lithium mica processing, and their energy consumption is reduced by 25% compared with ball mills.

Flotation equipment: The KYF-50 aerated mechanical agitator flotation machine has a processing capacity of 50m³/min, and the impeller linear speed is controlled at 6.5-7.5m/s, with high recovery rate and selectivity. The microbubble flotation column is used in the lithium mica concentration section, and the concentrate grade is increased by 2-3 percentage points.

Dehydration equipment: The deep cone concentrator is designed with a 45° cone angle, and the underflow concentration can reach 65%. The ceramic vacuum filter uses microporous ceramic plates, and the filter cake moisture is 3%-5% lower than that of traditional equipment.

3. Technology development trend

The current mineral processing technology is evolving towards intelligence and greening. XRT intelligent sorting technology realizes ore pre-disposal and reduces grinding energy consumption by 30%. The flotation process control system adjusts the reagent system in real time through an online analyzer, and the concentrate grade fluctuation range is narrowed to ±0.5%. Dry mineral processing technology is in the trial stage and is expected to completely solve the environmental protection problem of tailings ponds.

With the rapid development of the lithium battery industry, mineral processing equipment is upgrading to large-scale and efficient. The new flotation machine has a unit volume processing capacity of over 2t/(m³·h), and the ceramic filter has a single unit processing capacity of 60t/h. These technological advances have stabilized the spodumene recovery rate at 85%-90%, and the lithium mica recovery rate has increased to more than 75%, providing a solid resource guarantee for the new energy industry.