Copper Concentrate Specs for Chinese Smelters: What We Can Actually Ship from GB

A buyer from Yantai walked me through his rejection log last year. Seventeen cargoes flagged in twelve months. Not one for grade — every single one for arsenic, fluorine or lead penalties eating the deal alive.

That's the conversation I want to have here. Because when Chinese smelter procurement teams ask us about copper concentrate from Gilgit-Baltistan, they're not really asking about Cu%. They know we can hit grade. They want to know what else is riding along in the bag.

So let me be specific about what we can ship, what the geology gives us, and where the honest limits are.

The concentrate profile from our GB porphyry and vein systems

Our western Karakoram concessions sit in a belt with both porphyry-style mineralisation and higher-grade vein sets. The concentrate we're producing at pilot scale — and the material we're preparing for larger tonnage under JV structures — lands in the following envelope:

• Cu: 24–28% (we're targeting 25% as the contractual floor, with premium tiers above 27%)
• Au: 3–8 g/t in the concentrate, depending on feed blend
• Ag: 40–120 g/t
• Fe: 24–30%
• S: 30–34%
• Moisture: below 8% at load port

That's the clean part. Now the part buyers actually care about.

Arsenic runs 0.15–0.35% on our vein-hosted material and drops to 0.04–0.09% on the porphyry blend. Fluorine sits below 200 ppm in most of what we've assayed — we haven't hit the sericitic zones that usually cause F problems. Lead is under 0.5%, zinc under 1%, mercury effectively nil (we've been below 10 ppm across every batch tested at SGS Lahore).

Bismuth is where I'll be honest with you. Some of our vein material carries 300–600 ppm Bi, which is above the 500 ppm penalty threshold most Chinese smelters apply. We handle this by blending — porphyry-dominant feed dilutes the vein bismuth down to a payable level. If you're a smelter with tighter Bi limits (some of the Jiangxi Copper contracts I've seen sit at 300 ppm) we'd need to talk about a specific blend spec before signing anything.

What the GB geology actually gives you (and what it doesn't)

Here's the thing about our belt. The Kohistan-Ladakh arc runs east-west through our concessions, and the mineralisation we're working sits in a similar structural setting to the porphyry systems on the Tibetan side of the border. Chinese geologists reading this will already know what I mean — the arc chemistry is broadly comparable, which is why our arsenic profile on the porphyry material is manageable rather than catastrophic.

What we don't have, and I won't pretend we do, is the massive tonnage of a Chilean or Peruvian mine. Not yet. Our current realistic shipping capacity across the concessions I can commit to under a JV is 8,000–15,000 dmt per month of concentrate in year one, scaling toward 30,000 dmt monthly by year three with the right capex.

For a mid-sized Chinese smelter that's a meaningful secondary feed. For a Tongling or Jinchuan it's a diversification line, not a main artery. I'd rather say that plainly than oversell.

Logistics, and why this matters more than the assay sheet

A concentrate spec is worthless if you can't get the cargo to the wharf. Honestly, this is where most Pakistan copper export conversations fall apart, and I've watched deals die over it.

Our route: mine site to Gilgit, road haul down the Karakoram Highway to Havelian, rail or road to Karachi Port or Port Qasim. Truck cycle time from GB to Karachi is 7–9 days depending on winter conditions on the KKH. We containerise in 1-tonne bulk bags, 20 bags per 20-foot container, lined and sealed for moisture and IMO 8.2 compliance.

From Karachi to Chinese east-coast smelter ports (Fangchenggang, Yantai, Lianyungang) you're looking at 18–24 days on standard container liner routes. Gwadar changes some of this arithmetic — I've written about that separately — but for right now, Karachi is what actually works.

Loss on transit runs about 0.4–0.6% on moisture rebound and handling. We price that into contracts up front rather than fighting about it at the discharge port.

What we need from a serious buyer

If you're a smelter procurement lead or a trader positioning for Chinese offtake, here's what a first conversation with us looks like. You send me your standard spec sheet with penalty thresholds and payable curves. I send you back three things: our current assay range with 90-day rolling averages, a shipment schedule we can actually hold to, and the JV or offtake structure that fits your volume.

I got this wrong at first, by the way. Two years ago I was sending glossy resource summaries to buyers who just wanted to know one thing — can you hit 25% Cu, under 0.5% As, and land 5,000 tonnes at my port by Q2. Everything else was noise to them. Lesson learned.

The Chinese smelter market is the natural home for GB copper concentrate. Geographic proximity, existing trade rails through CPEC, and a technical spec that fits Chinese processing capacity better than it fits European smelters (who have tighter arsenic tolerances and typically want cleaner feed).

If your procurement team is looking at Pakistan copper export as part of a supply diversification play away from Latin American concentration risk, we should probably be on a call. What's your current penalty structure on As and Bi?