difference and application comparison between spray and roller pac

2025-12-01

Spray-dried and drum-dried Polyaluminum Chloride (PAC) exhibit significant differences in manufacturing processes, performance characteristics, and application scenarios. The following comparative analysis examines key parameters, supported by authoritative references:

1. Comparison of Production Technology and Physical Properties

● production engineering

Spray drying type: Liquid raw material is filtered by high pressure and then is atomized and dried by spray tower to form micron powder. Spray drying type: Liquid raw material is filtered by high pressure and then is atomized and dried by spray tower to form micron powder.

The drum type: the liquid raw material is naturally settled and then dried by the drum at high temperature to form irregular flakes or granules. The drum type: the liquid raw material is naturally settled and then dried by the drum at high temperature to form irregular flakes or granules.

● physical property

characteristic	spray drying type	Roller-drying type
surface	Ultrafine powder (white/light yellow)	Flaky granules (yellow/brown)
solution rate	Fast (homogeneous particles, easy to disperse)	Slower (requires longer stirring)
Dust problem	Obvious (fine powder easily disperses)	Lower (larger particles, less likely to cause dust)

Ⅱ. Differences in Chemical Properties and Effects

● Active ingredients and purity

Spray type: Alumina (Al2O3) content ≥30%, basicity 40-60%, water insoluble ≤0.3%; high purity, few impurities (especially low residual heavy metal).

Roll type: alumina content 26-30%, water insoluble matter ≤1.5%, salinity 80-95%; contains a small amount of iron ion (brown product), which may affect the color of effluent.

● flocculation effect

Spray type: hydrolysis fast, flocculent dense, sedimentation speed fast, effluent turbidity low.

Roller type: the molecular chain is longer, the adsorption capacity is strong, especially suitable for high turbidity sewage.

Ⅲ. Cost-effectiveness and Applicable Scenarios

● cost comparison

Spray type: the process is complicated, the energy consumption is high, the price is 30-50% higher than the roller type.

Roller type: Low production cost, unit price approximately 1800-2200 yuan/ton (industrial grade).

● Recommended use cases

type	Applicable fields	Common scenarios
spray drying type	High water quality standards and low impurity sensitive scenarios	Drinking Water Treatment, water for food/pharmaceuticals, paper sizing
Roller-drying type	High turbidity, high pollution, and cost-sensitive scenarios	Industrial wastewater (dyeing/metallurgy/mining), municipal sewage

● Key basis:

The spray type dosage is only 50% of the roller type, and the long-term use can reduce the comprehensive cost.

The decolorization effect of the drum type on the wastewater with high COD and high chroma is remarkable.

Ⅳ. Operational and Environmental Considerations

Operation convenience: Spray type dissolves quickly, but dust-proof equipment is needed;

Environmental impact: The spray type has less residual aluminum ions and is safer; the drum type contains impurities and requires controlled dosage to prevent secondary pollution.

Suggestions

Spray type: Recommended for high-standard applications like drinking water and precision industries when budgets allow.

Roller-type: Suitable for industrial wastewater, municipal treatment, and other cost-effective applications, or high-turbidity raw water.