A buyer who names calcium carbonate has named the mineral. The grade is the powder one process will accept: how it wets, how it disperses, and whether it stays white once the line has worked it. The mesh is the coarse fraction that process will not pass. A lot that has filled a joint compound, a plaster or a mortar can reach a compounder and fail to wet the resin. The same bags can reach a paint mill, fail to disperse, and shift off white after letdown. The paperwork can still read as carbonate. Calcium carbonate is offered when a qualified path matches the brief. Origin does not move the reject the plant already runs.
In French correspondence the mineral is carbonate de calcium. It is an industrial mineral, milled from limestone, marble or chalk, or taken as a precipitated powder when the line was qualified on that family. Ground or precipitated is settled in GCC or PCC. What is fixed here is the grade, the mesh the line will reject on, and where a sound lot fails once it leaves the industry it was bought for. Plastics, paint, paper, glass, a construction filler and agricultural liming each take their own powder.
When the powder in the formula is silica flour, clay, talc or another extender, this page is the wrong desk. Those briefs go to industrial fillers. A silica specification is rerouted and priced on the mineral it actually is. You bring the limits the plant already uses to refuse a lot. The shipment confirms them. If it cannot, the path is declined.
What you decide here
- Grade for one process: plastics, paint, paper, glass, a construction filler, or agricultural liming.
- Mesh as the reject you already run, with the sieve or the size method named beside it.
- Packing for this lot: bags, big bags, or a bulk hold, matched to the intake you have.
- Limits you will refuse a cargo for. A preference that will not stop a ship stays off the credit.
Name the process and the mesh limit you actually run in the trade inquiry. If you do not know whether the powder is GCC or PCC, say so rather than guessing.
The process picks the powder
The line picks the powder. The same stone can be milled for a mortar and, on another setting, for a film. Say which of those you are buying.
Name the plastics machine. Pipe, cable, sheet, film and masterbatch stop lots for different reasons. The filler has to wet in the melt, disperse, and hold colour. Moisture, a coarse tail, wear on screws and dies, and a surface treatment when the formula carries one, are the usual stops. A stearate coat and an uncoated construction powder are different products. Film shows a particle a thick wall hides.
A paint mill buys an extender, sometimes part of the pigment load. It judges grind, binder demand and colour after letdown. Masonry and a gloss enamel are separate orders. Coarse powder leaves grit and can flash. Very fine powder takes binder the formula does not spare, and viscosity moves. If the mill has already passed a carbonate, send that sheet and ask for a match.
Paper filler goes into the sheet. Coating has to clear a blade or a rod. A filler mesh on a coater marks the sheet while the assay still says carbonate. If the coater was set on a precipitated grade, say so. That question belongs on the GCC or PCC note. A ground lot stays ground.
Glass needs a size, plus an iron or silica limit filler contracts rarely carry. Agricultural liming needs a coarser material that will spread. Name lump stone or agricultural lime when that is the brief. A fine mesh sends the file down the filler path.
Joint compound, plaster, adhesive, dry-mix mortar, putty and asphalt filler allow more room. Moisture is often looser, and silo flow can matter more than colour. That grade is real. In a white compound it fails to wet, to disperse, or to stay white. One parcel for a paint blender, a compounder and a dry-mix site stacks three reject lists. Share it only when those lists agree.
Mesh is a reject line, not a decoration
Mesh is the screen the plant trusts: what should pass, and what residue must not. Two lots with the same mesh word can carry different coarse tails. The tail scratches film, flashes a gloss, and shows specks in a tinted compound. Arguments at discharge are usually about that tail.
Send a top cut, a residue on a named sieve, or a distribution point, with the method, when you control them. If you only have an old mesh habit, say so and leave the distribution empty. A number written to finish a form cannot be checked at loading.
An order that adds "high white" beside a mesh is a buying note. A thick section sometimes accepts coarser powder. A thin film stops on it. Write the condition that stops the cargo, and keep an unenforced wish out of the credit.
The mesh stays in the industry that qualified it. Mortar and masterbatch use different screens. Paper filler and a coater use different screens. Finer powder raises surface, so paint drinks binder, a melt can stiffen, and an open yard fills with dust. Send the mesh this process already runs.
This desk has no public mesh ladder. Send the limit you enforce. If a path can meet it, the offer names the test. If it cannot, the path misses the mesh and a neighbour powder is a separate offer. Put your sieve or your lab method next to the figure. "Fine" cannot be surveyed. If size is still vague, say what the operator sees: coarse bits in film, grit on the grind gauge, lumps on the silo screen.
Where a sound lot fails next door
The certificate can be clean and the next bay can still refuse the powder. The refusal shows up as wetting, as dispersion, or as white.
A compounder takes bags that filled a joint compound or a plaster. They look white. The papers say calcium carbonate. In the melt the powder sits in the resin, torque rises, and a tinted compound shows specks. Extra moisture brings steam and voids. The grade was bought for building products. The extruder sells wetting, dispersion and colour, and those are what just failed.
A paint mill meets the same miss with powder that had dispersed in a polyolefin. On the mill it may refuse the binder, or take more binder than the formula holds. The grind gauge finds grit the mesh word skipped. After letdown the white moves. Oil absorption, the coarse tail and colour after dispersion are separate stops. The mesh settles size. The mill settles the shipment.
A paper filler the wet end accepts will scratch a coater blade. Glass shows iron and a size that filler sheets usually skip. Powder that hides in a grey pipe can be the first mark in a glass melt. Agricultural lime is coarse so it will spread, and on a film line that particle is the defect. A film grade in a liming order buys liners and a fineness the field will not use.
The return direction costs as well. Ultrafine lined plastics powder in a putty mixer wastes the bag and dusts a yard with no collector. Iron hidden in a grey pipe streaks a white masterbatch. Moisture a dry-mix accepts becomes steam on a hot compounder. A shade a ceiling paint accepts becomes a claim on an architectural white. Coarse helps a mortar. On a film line it is what comes back.
Users who cannot share one reject list need two qualifications. A construction grade described as a plastics grade is still the construction grade. The plant finds the difference in the wetting, the dispersion, or the white.
Whiteness, moisture and what you will not test
Whiteness and brightness are different readings. Whiteness is often a colour-space figure. Brightness is often blue-light reflectance, used in paper and in some filler trades. A bright lot can still look yellow beside the chip a buyer signs. Name the method. "High white" cannot be surveyed.
Judge colour after the process. White in the sack can shift in a hot resin or after letdown. If iron moved the shade, name iron and the limit you enforce. Skip a ceiling copied from another origin if your lab has never run it. State carbonate directly, or from calcium oxide, and name magnesium if the stone leans dolomitic. "Pure", standing alone, is not a certificate line.
A grey pipe often has no use for a whiteness limit. A colour clause you will not enforce is a dispute waiting on the credit. Write the test when you sell a white or a tinted compound. Leave it off when you would never hold a ship for colour.
Moisture changes weight, silo flow, dispersion and the chance of steam. A dry-mix often accepts water a polyolefin line will refuse. State the limit, and say whether it is measured at loading or expected at arrival. Sea time, a torn liner and a loose cover all move the figure between those two points. "Dry" cannot be surveyed. If you will not reject on moisture, leave it off the credit.
Add oil absorption, a coating, pH, abrasion or loss on ignition only when the plant already runs that test. An unused limit becomes a third-party reject the operator does not recognise. Name the treatment if the grade is coated. The voyage will not put a coat on bare powder. A test that will not stop a ship stays off the credit.
NAGTAR does not publish a standing assay. Purity, mesh, whiteness and moisture belong to one grade and one lot. They are shared when the qualified supply can document them for this shipment. A figure from another origin is not this cargo. You bring the limits. The lot confirms them, or the path is declined.
Bags, big bags, or a bulk hold
Packing finishes the grade. Sound powder in the wrong pack arrives as a different product. Bulk suits a receiver who can take a hold. Bags and big bags suit the plant that cannot, and any lot that must stay identifiable from the load to the hopper. Fix the format for this lot once the grade and the intake are known.
A hold or a lined box needs a clean previous cargo, covers that seal, and discharge out of the rain. A wet skin cakes, loads the silo screen with lumps, and turns a weight claim into a water claim. Cement, clinker, coal or a coloured mineral ahead of the powder risks contamination. Dark specks can fail a white lot on sight while the carbonate content is unchanged.
Big bags carry a named grade when there is no silo, or when the lot must stay off powder the plant already trusts. Agree the lift weight, a liner if moisture is contractual, and a spout that fits. On a first buy, that separation is the trial. A hold tipped into the working silo cannot be pulled back the next day.
Small bags suit resale and hand dosing. They are a slow way to move industrial tonnes. Fine powder without a liner dusts the floor and the doors. Say when a coarser construction grade can travel with less protection, so the cheaper bag is a decision. If the resale market uses a small bag, say what a stack and a humid store will do to it.
Keep meshes on separate lines. A grab in the wind loses dust, and bags opened in the rain take on water the loading paper never showed. Write the discharge method beside the packing.
This page has no standard parcel, and it borrows no tonnage from cement or another mineral. Quantity is what this plant, this pack and this window can take. Big bags on a first lot are a working sample when the origin is new and the machine matches the bag. If a coating is contractual, the bag has to protect the surface. Water, a long air line and heat can change it while the assay stays put.
Send the process, not the formula
The formula names the molecule. Send the process the powder has to survive, and the rejects you will actually use.
One page is enough. English covers the specification, the packing and the terms. French is welcome when your sheets are already in French. Leave mesh words, colour words and the resin name as they were written. A nickname works once the limits sit beside it.
Name the process, then the line. Pipe, cable, film, sheet or masterbatch. Masonry or enamel. Paper filler or paper coating. A glass batch. Joint compound, plaster, adhesive, mortar, putty or asphalt. Liming, when the size has to spread. Say ground or precipitated if you know the family. If you do not, attach the sheet and mark the family unknown. A mesh is a weak basis for that guess, which is why the GCC or PCC note exists.
Send carbonate content, or the calculation your lab makes from calcium oxide. Send size with the method, and colour with the method when colour can stop a ship. Send moisture and where it is measured, any coating, and any other test you have already failed a lot for. Then packing, discharge, quantity, destination, the window, and whether the buy is a trial or a repeat.
One sentence on the last failure does more than a brochure. Coarse bits in film means the top cut has to be guarded. A drift toward yellow means iron and the colour method. "We need carbonate" names the mineral and leaves the grade blank. If the plant is still choosing between carbonate and silica, read calcium carbonate versus silica filler and say which way it leans. A silica flour brief opens on industrial fillers.
Keep one goods line on the contract, the credit and the bills. Mesh, coating and lined big bags have to appear where the bank will look. Bulk on a bill of lading, against lined bags in the contract, is a discrepancy before a sample is opened. An origin certificate satisfies customs. Mesh, colour and moisture sit on the certificate of analysis, with methods. A brochure is not that certificate. The qualified supply signs what this shipment can support.
The safety data sheet belongs in the warehouse file. Say who draws the sample and whose result governs if two labs disagree. An open jar from the quay is not a survey. On a new grade, run a pre-shipment sample in the extruder or on the grind gauge. Use the surveyor for weight, packing and the test list you wrote down.
Incoterms place cost and risk. The mesh and the bag stay in the goods line. Under FOB you take the ship, so the hold or the box still has to be fit. Under CFR risk passes at loading and insurance is yours unless you add it. Under CIF the named cover is often thin against wet bags. Name the discharge port in the inquiry, and keep a container grade on a container term.
Settle these before quantity. Each answer changes the lot that can be offered. Which process, and which line. Film and pipe, a coater and a wet-end filler, a glass batch and a paint extender: each pair is a different brief. Ground, precipitated, or unknown. The mesh limit that stops a cargo, with the method. Whether whiteness and moisture can stop a ship, and where moisture is measured. Whether the grade is coated. A hold, big bags, or small bags. A second user, and the property that user rejects. A trial you can keep apart, or a repeat already on the line.
A cheaper mesh, a missing liner, or bulk sent to a plant that doses from bags is another product under the old name. If the path can offer only a neighbour grade, the gaps show before a recap. Commitment is what that path can give in your window. This page has no capacity figure and borrows no tonnage from another mineral.
Copy this into the inquiry. Leave off any limit you will not enforce.
- Process and line: plastics, paint, paper, glass, a construction filler, or agricultural liming, named to the machine.
- Ground or precipitated, or unknown, with the sheet the plant runs today.
- Rejects you enforce: chemistry, size with the method, colour with the method, moisture, coating, and the last failure in one sentence.
- Packing and discharge: bags, big bags, or bulk, and how the powder will be unloaded.
- Quantity, destination, window, and whether the buy is a trial or a repeat.
- Any second user on the same lot, and the property that user rejects on.
Questions that change the lot
Does the inquiry need to be in French?
No. English covers the specification, the packing and the terms. Send French when your sheets are already in French, so the mesh and the colour words stay in one version. Leave the figures and the method names as they are printed. The desk reads the brief in the language the limits were written in.
Can one mesh serve plastics and paint?
Only when both plants have already run that grade on their own lines. Plastics stop lots on moisture, the coarse tail and dispersion in the melt. Paint stops lots on oil absorption, the grind and colour after letdown. The mesh can agree while those rejects do not. Qualify new users apart, and keep one as a trial the plant can isolate.
What if the powder needed is not CaCO3?
Name the mineral. Silica flour, clay, talc and fillers that still have no name start on industrial fillers. If the plant is choosing between carbonate and silica for one job, use calcium carbonate versus silica filler so the file asks for one rock. The inquiry is rerouted. A near-white powder ships under the name of the mineral it is.
Why did a cheap grade fail in a white compound?
The saving sat on the property the compound is sold on. Powder for joint compound, plaster or mortar is often coarser, duller, and packed for a site. In a white compound it shows as specks, a colour shift, or steam when the moisture is wrong for an extruder. The lot can still be calcium carbonate. Keep it on the line it was bought for, or qualify a grade the compounder has run.
Is bulk always the right packing?
No. Bulk fits a clean hold or a lined box, discharged clear of rain and of the previous cargo. Big bags fit when the lot must stay named, dry and separate, which is usual on a first buy and on a fine or coated powder. Small bags are resale or hand dosing. The format follows this grade and this discharge.
Will you publish one purity for Algerian carbonate?
No. Purity belongs to one grade and one lot. A single figure for the country would hide why a sound lot fails in the plant next door. Send the carbonate limit you enforce, and say how the lab calculates it. The desk will say whether a lot can be offered against that limit. Any result that follows is the result of that shipment.