Why buyers look beyond carbonized rice husk

The product description says the carbonized rice husk covering agent used in many steel mills has several problems. It spreads poorly, insulates poorly, tends to crust at the ladle mouth, and causes serious environmental pollution. These problems mean it no longer meets market demand under current environmental protection requirements.

The manufacturer describes its Environmentally friendly granule covering agent as having:

• good thermal insulation performance
• fast spreading speed
• no dust
• suitability for current environmental protection requirements

Step 1: Match the grade to the vessel

The product is listed in two varieties:

• Cover agent for ladles
• Cover agent for medium pack (the tundish, also called the intermediate or medium package)

The two grades have very different chemistry, so they are not interchangeable. Choose the grade based on where the material will be added.

Step 2: Compare the published chemical indicators

The source table does not state units. Confirm the units and test methods with the supplier. The table is marked "Or as requested," and the supplier says the product can be optimized for each plant to find a suitable ratio.

What the table shows for buyers:

• Carbon content (Cg) is the clearest difference. The ladle grade lists 10–20, while the medium pack grade lists ≤2. If your steel grades limit carbon pick-up in the tundish, discuss this with the supplier before you order.
• Al2O3 and SiO2 also differ. The medium pack grade has much higher Al2O3 (25–37) and lower SiO2 (≤15) than the ladle grade.
• If your plant's chemistry targets fall outside these ranges, ask for a custom ratio. Do not assume the standard grade will fit.

Step 3: Check the addition practice against your process

The manufacturer gives this usage guidance:

1. Ladle covering agent: add 1–1.5 kg per ton of steel to the molten steel surface before the ladle goes onto the caster.
2. Medium package (tundish) covering agent: add 150–200 kg once the casting liquid level of the first heat in the tundish meets the specified requirements. After that, add more as needed based on the liquid level, so the surface stays black.

Use these figures to estimate consumption, then confirm them against your own ladle sizes, tundish design and casting practice.

Step 4: Plan packing and logistics

The published packing options are:

• 1-ton jumbo bags, 18 tons per 20' container
• Bulk in container, 20–21 tons per 20' container
• 25 kg small bags inside jumbo bags, 18 tons per 20' container
• Other packing on customer request

The listed delivery ports are Tianjin and Qingdao, China.

A note on granule size

The related catalog listing "Eco-Friendly Particle Covering Agent" gives size options of 0–1, 1–3 and 3–5 mm. However, its composition table is incomplete in the available material. If granule size matters for spreading in your process, ask for the full size and composition sheet for the grade you plan to buy.

When this product may not fit

• Your process needs a covering agent with certified properties or third-party test data. None is included in the published material, so request documents before you approve the product.
• Your chemistry limits fall outside both published grades and no custom ratio has been agreed.
• You need a delivery port other than Tianjin or Qingdao, or packing that has not been agreed.

Pre-order checklist

• Which vessel will it be used in: ladle or tundish/medium pack?
• Units, test methods and tolerances for each chemical indicator
• Whether a custom ratio is needed for your plant
• Expected consumption based on the published addition rates
• Packing format and container load
• Delivery port, price, lead time and any documents you require

To discuss grade selection or a custom ratio, contact Xingtai Luxi Environmental Protection Technology Co., Ltd. with your vessel type, steel grades and chemistry targets.