LaycanDeskGranulated blast furnace slag freight: bulk and river barge
Unground GBFS on geared Handysize to Ultramax tonnage from Indian east coast, Chinese and Japanese steelworks to cement grinders, and the river-barge leg into Bangladesh. Freight for granulated blast furnace slag, the wet, sandy by-product cement grinders blend into slag cement: 27,000 to 61,500 tonne lots on geared Handysize, Supramax and Ultramax bulkers from Dhamra, Paradip and Haldia, from Rizhao and the Tangshan mills, and from the Japanese works, into Chattogram and Kutubdia lightering, Hambantota, Colombo and Cebu; and the Indo-Bangladesh Protocol barge route from Kolkata and Haldia to the river-side grinders around Narayanganj, at about 1,000 tonnes a barge.
Granulated slag is water-quenched at the furnace, so it ships damp: the Tata Steel data sheet works to IS 12089, 0 to 10 mm, glass content 90 per cent or more and moisture up to 14 per cent wet basis, and the freight is paid on that water. The IMSBC Code carries a schedule for granulated slag as a Group C cargo with a stowage factor of about 0.90 cubic metres a tonne, no special hazards beyond abrasive dust, and a bar on loading cargo warmer than 50°C; ground slag powder is a different cargo, a Group A schedule since the 07-23 amendment, and a shipper's declaration must say which one is being tendered. Holds are wanted clean and dry to cement-grade strictness, free of salt and coal residue, because the receiver grinds the slag straight into cement. Loading is by conveyor or grab, discharge by grab into hoppers; the ports on this trade have little shore gear, so geared ships do the work. Bangladesh is the largest destination in the world by mirror data, about 7.6 million tonnes in 2025 from China and India, and a Supramax cannot berth laden at Chattogram, so lots of 50,000 to 61,500 tonnes are lightered off Kutubdia and completed alongside. Sri Lanka and the Philippines take 27,000 to 36,000 tonne Handysize and Handymax lots at Hambantota, Colombo, Trincomalee and Cebu.
The second leg is inland. India moved 3.9 million tonnes of fly ash to Bangladesh grinders by barge in eleven months of 2022 on the Indo-Bangladesh Protocol route, about 1,000 tonnes a voyage, from Kolkata and Haldia towards Narayanganj, Pangaon and Ashuganj, and granulated slag has already moved from Kolkata on the same protocol. A rake from Jamshedpur delivers about 3,800 to 4,000 tonnes to the Khidirpur siding; the open point on slag is the loading pontoon, because the protocol jetties at Kolkata were built for pneumatic fly ash and slag needs a grab or conveyor. Send us the works and grade, quantity with tolerance, moisture basis, the IMSBC name on the shipper's declaration, load port and rate, discharge port with the lightering or barge arrangement and rate, laycan, commission and the charterer's name. Under CFR the mill or its trader fixes the ship and the grinder does not; on FOB the grinder or its Dhaka trader fixes. Ocean lots go to owners of geared Handysize to Ultramax tonnage opening in the Bay of Bengal, the China coast or Japan; the barge leg goes to protocol-registered operators, most of them Bangladeshi. The plant of origin is named first and every counterparty is screened before an owner sees the stem.
How it ships
- IMSBC 'Granulated slag': Group C, SF about 0.90 m³/t, not loaded above 50°C
- Ground slag powder is a separate Group A schedule; declaration decides
- Moisture up to 14% wet basis on the Indian TDC; freight on wet weight
- Conveyor or grab loading, grab to hopper discharge; geared ships
- Holds clean and dry, no salt or coal residue; last cargoes declared
- River barges about 1,000 t on the Indo-Bangladesh Protocol route
Load areas
- India east coast (Dhamra, Paradip, Haldia; Kolkata for barges)
- China (Rizhao, Tangshan mills via Caofeidian and Jingtang)
- Japan (Chiba, Kurashiki, Fukuyama, Kakogawa)
- Viet Nam (Son Duong, Dung Quat)
Discharge areas
- Bangladesh: Chattogram with Kutubdia lightering; Mongla
- Bangladesh river grinders: Narayanganj, Mukterpur, Meghnaghat by barge
- Sri Lanka: Hambantota, Colombo, Trincomalee
- Philippines: Cebu
- Malaysia and Singapore grinders
Ships that carry it
The cargo itself, on Commbril
Questions charterers and owners ask
Is granulated slag a Group A cargo?
Unground granulated slag is carried under the IMSBC schedule 'Granulated slag', Group C, with no liquefaction hazard, a stowage factor of about 0.90 cubic metres a tonne and a rule that cargo above 50°C is not loaded. Ground granulated slag powder is a different schedule, Group A since the 07-23 amendment, with a low transportable moisture limit. The shipper's declaration must name the schedule, and owners ask for it before they quote.
Why do owners ask about moisture on slag?
Because it is quenched with water and ships damp. The Indian data sheet allows up to 14 per cent moisture wet basis, and the cargo loses water on passage, so draft surveys at load and discharge disagree. Owners commonly price freight on the loaded figure or agree discharge weighing in the charter party; settle which before fixing.
How does a Supramax discharge slag in Bangladesh?
It does not berth laden. The 61,500 tonne cargo discharged in November 2025 was lightered off Kutubdia and completed alongside at Chattogram; cement inputs move from the outer anchorage by lighter as a rule. The grinder pays ocean freight, lighter freight and the anchorage handling, which is why river-side plants look at the barge route from Kolkata instead.
Can slag go to Bangladesh by river barge from India?
The protocol route already carries fly ash at scale, about 3.9 million tonnes in eleven months of 2022 at roughly 1,000 tonnes a voyage, to Narayanganj, Pangaon and Ashuganj, and granulated slag has moved from Kolkata on the same route. The open point is loading: the fly ash pontoons at Kolkata are pneumatic and slag needs a grab or conveyor berth. Tell us the grinder's jetty and its barge limits and we work the loading point with the Kolkata handlers.