GN Trash Screen – Enhancing Iron Ore Flotation Efficiency by Removing Impurities

In iron ore beneficiation, maintaining clean and stable feed quality is essential for achieving high flotation efficiency and stable plant performance. Before ore enters the flotation stage, impurities such as grass roots, bark, plastic fragments, and even explosive fuse remnants can severely affect downstream operations. These contaminants not only reduce flotation efficiency but also lead to equipment blockage, downtime, and increased maintenance costs.

To address these issues, GN Separation offers the GN Trash Screen (Model: GNGZ1840A), a purpose-built solution designed to safeguard the purity of raw ore materials before flotation.

Efficient Impurity Removal for Iron Ore Processing

The GNGZ1840A Trash Screen is engineered specifically for impurity removal in iron ore preparation plants. It combines powerful vibration with a durable, purpose-designed screen deck to effectively separate unwanted materials from the ore stream.

Key Benefits:

1. Reliable Separation of Undesirable Materials

The screen efficiently removes light and fibrous contaminants such as:

  • Grass roots

  • Bark and wood pieces

  • Plastic or foreign soft materials

  • Explosive fuse fragments

These impurities often originate from mining, blasting, and transportation. Removing them at the earliest stage protects the downstream process.

2. Improved Flotation Concentrate Quality

By maintaining a cleaner feed, the flotation process becomes more stable and selective. Cleaner ore slurry directly contributes to:

  • Higher iron grade

  • Reduced reagent consumption

  • Lower risk of interference in flotation cells

3. Reduced Equipment Downtime

Trash materials can easily cause pump blockages, pipeline choking, and screen blinding. The GN Trash Screen helps operators significantly reduce:

  • Unplanned shutdowns

  • Maintenance frequency

  • Wear on downstream equipment

This results in lower operating costs and higher overall plant availability.

Robust Structure and Reliable Performance

The GNGZ1840A Trash Screen features:

  • Strong vibration force for efficient stratification

  • Reinforced screen box suitable for heavy-duty mining applications

  • Customized screen panels designed to balance strength, permeability, and wear resistance

  • Stable operation even under fluctuating feed conditions

Every component is engineered to withstand harsh mining environments, ensuring long service life and consistent performance.

GN Separation – Complete Solutions for Mining and Mineral Processing

GN Separation provides a comprehensive range of solid–liquid separation and classification equipment for the mining industry. Beyond the Trash Screen, GN offers a wide portfolio of mineral processing solutions, including:

1. Mining Vibrating Screens

GN manufactures several types of vibrating screens for classification, dewatering, and desliming applications:

  • High-frequency vibrating screens

  • Large flip-flow vibrating screens

  • Synergistic frequency vibrating screens

  • High shear circular screens

These screens are designed to handle fine materials, high-moisture feeds, and demanding capacity requirements.

2. Tailing Management Solutions

GN provides decanter centrifuges specifically developed for:

  • Tailing dewatering

  • Recovery of valuable solids

  • Sludge volume reduction

The machines feature rugged construction, wear-resistant materials, and automation options for stable tailing treatment.

3. Material Transfer Equipment

To support mining plant logistics, GN also offers:

  • U-Type screw conveyors

  • Progressive cavity pumps (single screw pumps)

  • Vacuum pumps for solids and slurry transport

These systems streamline material handling and ensure smooth operations across processing lines.

Conclusion

The GN GNGZ1840A Trash Screen is a crucial piece of equipment for iron ore beneficiation plants, protecting flotation processes from contaminants and ensuring high-quality concentrate production. Its strong separation capacity, durable design, and consistent performance make it an essential tool for maintaining operational efficiency.

Combined with GN’s extensive range of mining-class screening, dewatering, and conveying equipment, GN Separation continues to deliver reliable, industry-proven solutions for mineral processing plants worldwide.

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4 Units GNLW554-VFD Dewatering Centrifuge Delivered to an Overseas Sewage Treatment Plant

GN Separation recently completed the delivery of four units of GNLW554-VFD dewatering decanter centrifuges to an overseas municipal sewage treatment plant. This project marks another milestone in GN’s continuous effort to support global wastewater treatment facilities with reliable solid-liquid separation solutions.

Enhancing Sludge Dewatering Efficiency

Municipal wastewater treatment plants generate large volumes of sludge every day. Efficient dewatering is essential to reduce sludge volume, lower transportation and disposal costs, and improve overall treatment performance.

The GNLW554-VFD decanter centrifuge is specifically engineered for high-capacity sludge dewatering. Its large-diameter rotating bowl and optimized beach angle enable effective separation, even with materials containing high moisture and complex solids content.

Key performance strengths include:

  • Large processing capacity suitable for municipal and industrial sludge

  • High separation efficiency supported by a long bowl length-to-diameter ratio

  • Stable operation under continuous heavy-duty working conditions

  • Lower polymer consumption compared to traditional dewatering methods

These advantages make the GNLW554-VFD an ideal choice for medium to large wastewater treatment facilities.

VFD Control System for Process Flexibility

All four units are equipped with a Variable Frequency Drive (VFD) control system. This allows users to adjust bowl speed, differential speed, and feed rate based on the characteristics of the sludge.

Benefits of the VFD system include:

  • Precise control of separation performance

  • Energy efficiency through optimized motor speed

  • Capability to handle varying sludge conditions throughout the day

  • Automatic protection functions, including vibration monitoring and overload alarms

For wastewater plants that operate around the clock, such flexibility greatly improves cost-effectiveness and reliability.

Robust Materials for Municipal Wastewater Applications

The GNLW554-VFD centrifuge is built with corrosion-resistant materials suitable for the challenging environment of sewage treatment plants. Typical material configurations include:

  • Stainless steel bowl and scroll manufactured by centrifugal casting

  • Tungsten carbide protection on wear-prone components

  • High-quality bearings from internationally recognized suppliers

  • Optional duplex stainless steel or super duplex materials for aggressive wastewater conditions

This ensures long service life and reduced maintenance requirements.

Supporting Global Wastewater Treatment Projects

GN Separation has been supplying decanter centrifuges to various municipal and industrial wastewater projects around the world. The successful delivery of these four GNLW554-VFD units further demonstrates GN’s capability to support international partners with professional equipment and technical expertise.

With growing global attention on safe water treatment and environmental protection, GN Separation remains committed to providing efficient, reliable, and user-friendly solid-liquid separation solutions.

Unlocking Efficiency: GN Separation’s 13 Units of 5-Deck Stack Vibrating Screens for Ilmenite Ore Classification

As mineral processing projects continue to demand higher efficiency and finer classification, GN Separation is proud to announce the delivery of 13 units of 5-deck stack vibrating screens for a large-scale ilmenite ore classification project. This milestone highlights GN’s commitment to providing reliable, high-performance screening solutions for the miningindustry.

Importance of Accurate Ilmenite Classification

Ilmenite is a major titanium-bearing mineral used widely in the production of titanium dioxide, a key material for paints, coatings, plastics, and aerospace applications. Effective classification during ore preparation is essential to ensure high recovery rates and stable product quality. GN’s multi-deck screening technology is designed to meet these demands by offering high-capacity, fine particle separation in a compact configuration.

Key Features of GN’s 5-Deck Stack Vibrating Screen

GN’s stack vibrating screen—also known as a stack sizer—is specifically developed for wet screening and fine classification of mineral ores. Each of the 13 units supplied for this project incorporates the following features:

1. High-Efficiency Multi-Deck Design

Each screen consists of five individual screening decks, allowing simultaneous separation of multiple size fractions while maintaining a small footprint.

2. High-Frequency Linear Vibration

Driven by two synchronized vibration motors, the screen operates through a two-degree-of-freedom resonance system. This design achieves high vibration strength, reduces screen blinding, and improves separation efficiency for fine and challenging materials.

3. Durable Polyurethane Screen Mesh

Each deck is equipped with high-strength polyurethane (PU) mesh panels known for their flexibility, anti-blocking performance, and long service life.

4. Modular Construction for Easy Maintenance

The feeding distribution box and screen frames are modular and easy to assemble or replace, enabling maintenance on individual decks without disassembling the entire unit.

5. Enhanced Wear and Corrosion Resistance

The screen surfaces are coated with a protective layer, and all structural components are treated to withstand abrasive and corrosive mining environments.

Benefits for Ilmenite Processing

For ilmenite classification, GN’s 5-deck stack vibrating screen provides several key advantages:

  • Stable and accurate particle size separation

  • Efficient handling of high-throughput slurry

  • Reduced processing footprint due to vertical stacking

  • Lower operating and maintenance costs through a durable, service-friendly design

  • Improved downstream performance for magnetic separation or flotation

By using multi-deck high-frequency screening, mineral processors can achieve higher recovery rates and better product consistency—critical factors in titanium ore beneficiation.

Supporting Global Mining Projects

With manufacturing facilities, engineering centers, and service teams in multiple regions, GN Separation continues to support global mining clients with customized screening solutions and responsive after-sales support. The successful delivery of these 13 screening units further strengthens GN’s role as a trusted partner in the mineral processing industry.

GNLW364-VFD Dewatering Centrifuge for Overseas Pharmaceutical Plant Wastewater Treatment

IntroductioIn the pharmaceutical industry, wastewater streams often pose complex separation challenges. High levels of organics, biological materials, fine solids and chemical residues must be treated efficiently to meet regulatory and environmental standards. The GN Separation GNLW364-VFD decanter centrifuge addresses these challenges with a design focused on dewatering and reliable performance in demanding applications. According to GN’s recent news, a batch of GNLW364 units has been assembled for shipment to an overseas pharmaceutical plant wastewater treatment project. Why a High-Performance Dewatering Centrifuge Matters

For pharmaceutical wastewater, the solids content may vary, particle sizes can be fine, and the sludge may include aggressive chemicals and solvents. Using a robust decanter centrifuge helps:

  • Reduce sludge volume and footprint of sludge disposal.

  • Recover clarified water for reuse or safer discharge.

  • Increase solids dryness, improving transport and disposal cost efficiency.

  • Manage variations in feed (viscosity, density, concentration) thanks to advanced control systems.

According to GN’s site, decanter centrifuges perform well where high throughput, high dryness, and reliable operation are required.

Key Features of the GNLW364-VFD Model

Here are some of the standout features of the GNLW364-VFD (and related models) that make it well suited for pharmaceutical plant wastewater treatment:

1. Duplex stainless steel bowl (SUS 2205) construction
The bowl and screw end caps are made of duplex stainless steel (SUS 2205 or SUS 2304) produced via centrifugal casting. This provides superior corrosion resistance and mechanical strength compared to SUS 304 or SUS 316.

2. Wear ­protection via tungsten carbide sleeve & special screw blade design
The screw conveyor’s blade is pressed rather than drawn, improving conveying efficiency. A hard tungsten carbide sleeve protects the solids discharge port from abrasion. These design aspects support longer service life—critical when handling abrasive particulates, chemical sludges or mixed wastewater streams.

3. Optimised geometry – 8.5° beach angle, long drying zone
The T‐series dewatering decanter (which includes models like GNLW364) uses a beach angle of 8.5°, which lengthens the drying zone of the bowl and enhances dewatering performance (i.e., drier cake, clearer liquid).

4. Variable Frequency Drive (VFD) control & monitoring
The “VFD” designation highlights the use of variable frequency drives, enabling fine tuning of bowl speed, screw (differential) speed and feed pump rate. Real‐time monitoring of temperature, vibration, lubrication and other key parameters improves operational safety and consistency of performance.

5. Turnkey capability & customisation
GN states that besides supplying the dewatering decanter centrifuge, they can deliver full dewatering solutions—including material transport, classification and dewatering systems. This is especially valuable for complex wastewater treatment setups in the pharma sector.

Application in an Overseas Pharmaceutical Plant

In the referenced project, GN has assembled GNLW364‐VFD units destined for a pharmaceutical client’s wastewater treatment facility.

Here’s how the features align with typical pharma‐waste water demands:

  • Chemical & biological solids: Pharmaceutical wastewater can contain residuals from active pharmaceutical ingredients (APIs), excipients, solvents, biological media and fine solids. The high-G-force and efficient screw conveyance of the GNLW364 help manage these.

  • Abrasion & corrosion risks: With mixed chemicals and potentially abrasive particulates, the use of duplex stainless steel and wear protection ensures longevity.

  • Fluctuating feed conditions: Flow rates, solid concentrations and sludge characteristics change over time. The VFD control allows the decanter to adapt.

  • Regulatory and reuse demands: Pharmaceutical sites often target water reuse, meaning clarified effluent quality is important. The longer pool depth and extended dewatering shell improve clarity as well as dryness.

  • Minimised downtime & labour: Features like hydraulic disassembly for main bearings, gas‐spring assisted lids, and automatic lubrication support easier maintenance and operational reliability.

Benefits for the Client

By deploying the GNLW364-VFD, a pharmaceutical plant can expect:

  • Lower disposal costs: Drier solids mean less volume and lower transport/disposal costs.

  • Water recovery: Higher clarity liquid can be reused or discharged with less treatment.

  • Operational efficiency: Automation and monitoring reduce manual maintenance and risk of failure.

  • Durability: Premium materials and wear protection lower lifetime maintenance costs.

  • Tailored solution: A decanter designed and sized according to actual sludge characteristics ensures better performance than a generic machine.

Considerations for Implementation

While the equipment offers many strengths, proper implementation is essential:

  • Accurate feed characterisation: Particle size, specific gravity, viscosity, solids concentration and fouling risk must be assessed to select the right screw pitch, beach length, differential speed and pool depth.

  • Flocculation/pre‐treatment: As the GN spec states, fine particles may need flocculants to aggregate before dewatering.

  • Maintenance access and wear part planning: Even with wear protection, scheduled maintenance and spare part strategies should be in place (screw flights, tungsten carbide liners, bearings).

  • Control integration: The VFD/PLC/HMI system should be integrated with the plant’s control architecture and operators trained.

  • Waste stream variability: For pharmaceutical plants, seasonal or batch variations may occur; flexible control helps but oversight and process tracking are key.

Conclusion

For a pharmaceutical wastewater treatment application overseas, the GNLW364-VFD dewatering decanter centrifuge from GN Separation delivers a purposeful combination of durability, flexibility, and performance. Its design is aligned with the demands of the pharma sector—fine solids, variable streams, high regulatory expectations—and it supports water reuse and sludge volume reduction goals.

If you’re involved in wastewater treatment for a pharmaceutical plant or managing separation challenges, diving into the GNLW364-VFD’s specifications, conducting a site‐specific evaluation, and working with a supplier who offers full system support (as GN does) can set you up for success.

Two Sets of 240 m³/h Trenchless Mud Treatment Systems Delivered to an Australian Customer

Recently, GN Separation successfully delivered two sets of 240 m³/h trenchless mud treatment systems to a customer in Australia. Each system is designed to efficiently process drilling and trenchless construction mud, ensuring effective recycling and reuse.

Each System Includes:

These systems are designed for trenchless drilling and horizontal directional drilling (HDD) projects, where efficient solids control and fluid recovery are critical for cost reduction and environmental compliance.

Double-Deck Vibrating Screens — The Core Equipment

Each mud treatment system is equipped with two double-deck vibrating screens, which serve as the key equipment for primary solids separation. The vibrating screens remove large solids from the drilling mud, ensuring that the downstream desander and desilter units receive mud with lower solids content, thus improving the overall separation performance.

Technical Features

The double-deck vibrating screen shares design concepts with GN’s high-performance vibrating screen range, as described on GN Solids Australia’s website. The main technical features include:

  • Double-Deck Structure:
    Two screening decks are driven by a single vibration source, providing larger screening area and enabling two-stage separation or finer solids removal within limited space.

  • Linear Vibration Motion:
    The screen box operates in a linear motion pattern, ensuring efficient material conveyance and effective solids discharge. This motion type is ideal for treating slurry and liquid-solid mixtures.

  • High-Quality Polyurethane (PU) Screens:
    PU screens offer excellent wear resistance, elasticity, and self-cleaning properties. The high open area (typically 28–45%) ensures efficient screening while minimizing blinding.

  • Compact and Space-Saving Design:
    The double-deck design allows higher processing capacity within a smaller footprint — an important advantage at job sites with limited space.

  • Dual-Motor Self-Synchronization Drive:
    Two vibration motors work in self-synchronization to ensure stable operation and uniform vibration, reducing maintenance and energy consumption.

  • Anti-Corrosion and Wear-Resistant Surface Treatment:
    The screen box is treated with sandblasting, heavy-duty anti-corrosion coating, and a polyurea wear layer on surfaces exposed to mud, ensuring long service life in harsh field environments.

Application Advantages in This Project

The inclusion of double-deck vibrating screens in this system offers several operational benefits:

  • Higher Primary Solids Removal Efficiency:
    Coarse solids are quickly separated, reducing the solids loading on the desander and desilter units, and improving the overall treatment performance.

  • Reduced Footprint and Structural Height:
    Compared with two single-layer screens, the double-deck design saves space while maintaining large screening capacity — ideal for compact trenchless job sites.

  • Stable and Continuous Operation:
    Linear motion and flexible PU screens prevent blinding and ensure consistent performance, minimizing downtime and maintenance needs.

  • Energy Efficiency and Easy Maintenance:
    The simple structure, synchronized drive, and long-lasting screens help reduce operational and maintenance costs.

  • Customizable Design:
    The vibrating screen can be customized based on the site’s mud properties (solid content, particle size distribution, viscosity, etc.) by adjusting screen mesh size, vibration amplitude, and feeding mechanism.

Technical Reference

While this project uses double-deck vibrating screens, their design principles align with GN’s multi-deck (2–5 layers) vibrating screens, as shown on the GN Separation official website:

  • Screen angle: 17.5°

  • Vibration frequency: ~25 Hz

  • Double amplitude: 1–2 mm

  • Mesh size range: 0.045–2 mm

  • Material: Polyurethane or stainless steel mesh

These parameters ensure high efficiency, precision, and stability in fine particle separation.

Operation and Maintenance Recommendations

To achieve the best field performance, GN recommends:

  • Even Feeding: Install a buffer box or flow divider at the feed inlet to distribute slurry evenly across both decks.

  • Regular Cleaning: For sticky or high-sand-content mud, equip the screen with a spray cleaning system to prevent clogging.

  • Screen Inspection: Periodically check screen tension, mesh integrity, and fastening bolts.

  • Monitor Vibration System: Keep track of motor temperature, vibration frequency, and amplitude to prevent imbalance.

  • Easy Access Maintenance: Design the platform for convenient screen replacement and motor servicing.

Project Highlights & Customer Benefits

  • High Processing Capacity: 240 m³/h throughput per system meets demanding trenchless operations.

  • Compact Modular Design: Facilitates transportation, installation, and integration with existing job site systems.

  • Improved Mud Recycling Efficiency: Ensures better fluid recovery and cleaner mud for reuse, reducing waste disposal costs.

  • Reliable and Durable: Built with robust materials and proven GN manufacturing standards.

  • Localized Support: GN’s technical and after-sales teams provide professional guidance for installation and commissioning in Australia.

Summary

The successful delivery of these two systems demonstrates GN Separation’s strong capability in providing efficient and reliable trenchless mud treatment solutions. With advanced design, durable equipment, and proven field performance, GN Separation continues to support clients in Australia and worldwide in achieving cleaner, more sustainable construction operations.