Selecting a nickel sulfate FIBC involves more than comparing load capacity, fabric weight, or price. Two bags may both be described as 1000 kg FIBCs, but different material conditions, filling equipment, storage periods, and discharge processes can require different dimensions, liners, and spout configurations.

A practical selection sequence is:

Material condition → Filling process → Storage and transportation → Discharge → Final bag configuration

This framework converts operating conditions into defined FIBC requirements.

Step 1: Confirm the Nickel Sulfate Condition

Material Form and Particle Size

First confirm whether the nickel sulfate is supplied as powder, crystals, or granules. Fine powder places greater emphasis on:

• Coated or uncoated body fabric;
• PE inner-liner requirements;
• Liner tying or heat sealing;
• Additional dust-control construction around seams;
• Enclosed filling and discharge connections.

Crystalline or granular material may require additional consideration of particle edges, flowability, and friction against the liner. The material name alone is not enough to determine the bag structure.

Bulk Density Determines Bag Volume

The target filling weight should be evaluated together with bulk density:

$$\text{<span style="font-size:16px;"><span style="font-family:arial,helvetica,sans-serif;">Required effective volume</span></span>}<span\; style="font-size:16px;"><span\; style="font-family:arial,helvetica,sans-serif;">=</span></span>\frac{\text{<span style="font-size:16px;"><span style="font-family:arial,helvetica,sans-serif;">Target filling weight</span></span>}}{\text{<span style="font-size:16px;"><span style="font-family:arial,helvetica,sans-serif;">Material bulk density</span></span>}}$$text{Required effective volume} = frac{text{Target filling weight}}{text{Material bulk density}}

Two nickel sulfate materials with the same target weight may require different effective volumes. Actual material data should be provided before confirming the bag length, width, and height.

Material-Protection Requirements

The buyer should also define requirements related to:

• Environmental humidity;
• External contamination;
• Dust escape;
• Inner-surface cleanliness;
• Liner material and thickness;
• Electrostatic control;
• Storage duration.

A coated outer bag and PE liner can create a multilayer isolation structure, but they should not be described as completely moisture-proof, airtight, or leak-free without relevant testing.

Step 2: Determine the Inlet from the Filling Process

Filling-Equipment Interface

Measure the filling-equipment outlet diameter, installation height, and effective connection length. The filling spout must fit or attach to the equipment outlet while allowing space for a tie, clamp, or other closure.

For example, a Ø45 × 60 cm filling spout provides two dimensions:

• Ø45 cm: spout diameter;
• 60 cm: spout length.

The diameter affects interface compatibility, while the length affects overlap, fastening, and closure after filling. This is one possible order configuration rather than a universal size.

Filling Method and Rate

The equipment outlet should be aligned with the center of the bag to limit off-center filling and uneven bag shape.

Electrostatic Conditions During Filling

Powder flow, friction, and pneumatic conveying may generate electrostatic charge. The buyer should clarify whether an anti-static additive is sufficient or whether a defined surface resistance, FIBC electrostatic type, or third-party report is required.

A 2% anti-static additive is formulation information. It does not by itself establish a Type B, Type C, or Type D classification. Applications involving combustible dust, flammable vapours, or hazardous areas require an FIBC and liner configuration based on IEC 61340-4-4 and a site-specific risk assessment. 

Step 3: Match the Outer Bag, Liner, and Loops to Storage and Transportation

Storage Period and Environment

The buyer should specify the expected period between filling and discharge and whether the bags will be stored indoors, in a partially open area, or outdoors.

Confirm:

• Warehouse humidity and temperature changes;
• Damp floors or condensation;
• Sunlight through windows or skylights;
• Temporary outdoor storage;
• Sea transportation and container condensation;
• PE-liner closure method.

A UV-additive ratio cannot be converted directly into a fixed number of months of outdoor use. Longer sunlight exposure requires defined ageing conditions and strength-retention data.

Pallets and Storage Space

Bag dimensions should be checked together with pallet, warehouse, and transportation dimensions. A nominal size such as 93 × 93 × 105 cm may expand laterally after filling, so the maximum filled dimensions should be used for warehouse and loading calculations.

The buyer should provide:

• Pallet length and width;
• Forklift-entry direction;
• Warehouse vertical clearance;
• Required bags per row;
• Truck or container internal dimensions;
• Stacking requirements.

A fixed stacking level should not be stated without finished-bag testing and confirmation of supporting conditions.

Handling and Lifting Structure

For frequent forklift transfer, confirm:

• Number of lifting loops;
• Loop height;
• Fork width and spacing;
• Whether cross-bottom belts are required;
• Interaction between the discharge spout and lifting belts;
• Expected lifting frequency;
• Use of a lifting beam.

Cross-bottom lifting belts extend the load path beneath the bag, but finished-bag performance must still be evaluated using the fabric, seams, belts, and applicable tests.

Step 4: Determine the Outlet from the Discharge Process

Downstream Equipment Interface

The discharge spout should match the inlet of the receiving hopper, pipe, or processing equipment. The downstream inlet diameter, installation height, and connection method should be provided.

A Ø45 × 45 cm discharge spout has a 45 cm diameter and 45 cm length. Its suitability depends on material flowability and downstream equipment, not on diameter alone.

Material Flowability

Before selecting the outlet, determine whether the nickel sulfate tends to:

• Agglomerate;
• Bridge;
• Compact;
• Remain in the bottom corners;
• Flow freely;
• Generate noticeable dust.

Material with limited flowability may require a larger outlet or assisted-discharge equipment. Free-flowing fine powder may require greater control of discharge rate, outlet closure, and enclosed connection.

Complete or Partial Discharge

For complete discharge, the outlet can be configured for fast connection and full emptying. For partial batch feeding, confirm whether the discharge spout and liner outlet can be reclosed.

Step 5: Build the Final Bag Configuration

Example Nickel Sulfate FIBC Configuration

The following is a reference configuration used to illustrate the selection framework. It is not a universal specification for every nickel sulfate application.

Buyer Decision Checklist

Before confirming the final configuration, provide:

1. Nickel sulfate form and particle size;
2. Actual bulk density;
3. Target net weight and permitted tolerance;
4. Filling-equipment outlet dimensions and installation height;
5. Filling method and target filling rate;
6. Dust and electrostatic-control requirements;
7. Storage environment and expected duration;
8. Pallet, warehouse, and transportation dimensions;
9. Forklift or lifting-equipment parameters;
10. Downstream-equipment inlet and discharge method;
11. PE-liner material, thickness, and closure;
12. Printing, labelling, and batch-traceability requirements.

The objective is not to find one “standard bulk bag,” but to convert material, equipment, storage, and logistics conditions into a bag configuration that can be confirmed and tested.