Scraper Bottom Discharge Centrifuge for Borate and Specialty Mineral Salt

The Scraper Bottom Discharge Centrifuge is designed for batch solid-liquid separation, cake washing, spin drying, and automatic bottom discharge of borate crystals and specialty mineral salts.

It is suitable for filterable crystalline products generated by evaporation, cooling crystallization, reaction crystallization, brine concentration, and mineral salt recovery processes. Typical materials include borax crystals, boric acid crystals, sodium metaborate, mixed borate salts, sulfate-bearing mineral salts, chloride-bearing mineral salts, and other inorganic crystalline products requiring controlled mother liquor removal.

The centrifuge is particularly suitable for specialty mineral salt projects where product purity, crystal integrity, controlled washing, mother liquor recycle, and stable batch operation are important.

Peony provides the solid-liquid separation section for borate crystal recovery and specialty mineral salt processing after evaporation, crystallization, reaction, or brine concentration.

Crystallizer / Evaporator → Agitated Slurry Tank → Controlled Feed → Scraper Bottom Discharge Centrifuge → Mother Liquor Recycle / Purge → Optional Cake Washing → Automatic Bottom Discharge → Dryer / Cooler / Screen / Storage

Peony can provide:

• Crystal slurry buffer tank with agitator
• Controlled feed system for stable cake formation
• Filter basket and filter medium selection
• Optional in-basket cake washing system
• Filtrate collection and mother liquor recycle connection
• Automatic scraper discharge mechanism
• PLC control system with programmed batch sequence
• Safety interlocks and machine protection system
• Connection to dryers, coolers, screens, conveyors, silos, or packing lines
• Customized wetted materials according to liquor chemistry and operating conditions

1. Crystal Slurry Feeding

Borate or specialty mineral salt slurry enters the rotating basket through a controlled feed system.

The feed rate is adjusted to support even crystal distribution and avoid excessive turbulence or crystal breakage.

2. Mother Liquor Filtration

Under centrifugal force, the liquid phase passes through the selected filter medium and basket perforations.

The separated mother liquor is collected through the filtrate outlet for recycle, purge, recovery, or further treatment.

3. Crystal Cake Formation

The crystals remain inside the basket and build up as a filter cake on the basket wall.

Cake quality depends on crystal size, fines content, slurry solids concentration, liquid viscosity, and filter medium selection.

4. Optional Cake Washing

Compatible wash liquid can be applied to the crystal cake when lower mother liquor carryover or improved product purity is required.

The washing step can reduce soluble impurities trapped between crystals before drying or further processing.

5. Spin Drying

After filtration and optional washing, the basket continues rotating to reduce free liquid retained in the cake.

Lower retained liquid can reduce downstream drying demand and improve product handling.

6. Automatic Scraping

When the programmed separation cycle is completed, the scraper removes the dewatered crystal cake from the basket wall.

7. Bottom Discharge

The recovered borate or mineral salt crystals are discharged automatically through the bottom outlet and transferred to the next process stage.

Suitable for Crystalline Borate and Mineral Salt Products

The centrifuge is designed for filterable crystals that need controlled dewatering, washing, and discharge after crystallization.

It is suitable for batch processing where stable crystal recovery and repeatable product handling are required.

Optional Cake Washing for Improved Product Cleanliness

An in-basket washing system can reduce residual mother liquor, dissolved impurities, and unwanted soluble salt carryover.

This is useful for borate products and specialty mineral salts that require cleaner crystal surfaces before drying, screening, storage, or packaging.

Automatic Bottom Discharge

The scraper system removes the crystal cake automatically after each batch cycle.

This reduces manual handling and improves operating consistency compared with manual top-discharge centrifuges.

Lower Retained Mother Liquor

Filtration and spin drying reduce the amount of mother liquor remaining in the crystal cake.

This helps reduce downstream dryer load and can improve storage stability for moisture-sensitive products.

Flexible Filter Medium Selection

The filter basket and filter medium can be matched to crystal size distribution, fines content, cake permeability, and washing requirements.

This is important for specialty salts where crystal morphology can vary between operating campaigns.

Can this centrifuge process borax crystal slurry?

Yes. The centrifuge can be configured for borax crystal dewatering when the slurry produces a stable and filterable crystal cake. Basket design, filter medium, washing sequence, and cycle time should be selected according to crystal size and mother liquor properties.

Can it be used for boric acid crystal separation?

Yes. It can be considered for boric acid crystal separation when the product has suitable filtration behavior. Product solubility, wash liquid compatibility, crystal size, and material selection should be reviewed during process design.

Can borate crystals be washed inside the centrifuge?

Yes. An optional in-basket washing system can reduce residual mother liquor and soluble impurities. The wash liquid must be selected carefully to avoid excessive product dissolution or unwanted crystal changes.

What happens to the separated mother liquor?

The separated liquor can be returned to the crystallizer, evaporator, mother liquor tank, brine concentration section, controlled purge stream, or further recovery system.

Can the centrifuge connect directly to a dryer?

Yes. The automatic bottom discharge can connect to a dryer, cooler, vibrating screen, screw conveyor, belt conveyor, storage bin, or packaging system based on the plant layout.