Looking at Cardox® for Rock Breaking? Same principle — factory-direct alternative
Explosives vs. Liquid CO2
Yes — the liquid CO₂ phase-change principle behind Cardox® tubes (600–1,000× volume expansion, 200–300 MPa) is available factory-direct from China in both reusable and disposable forms: DL-51 for boiler-ash and silo desilting, DL-108 for deep-hole rock breaking, and the #90 disposable metal tube for sites that must use true liquid CO₂ but do not want to recover tubes. A separate 32/40 mm gas-expansion tube (chemical powder, not liquid CO₂) covers small and temporary jobs without CO₂ logistics — at a fraction of imported-system budgets.
Affiliation notice: “Cardox®” is a registered trademark of its respective owner. This independent comparison is published by ZD Rock Breaking and is not affiliated with or endorsed by that owner. Trademarks are used only to identify the product category.
The principle is the same — and it has a 100-year track record
The gas-expansion rock breaking method behind Cardox® tubes is well documented: a steel tube is charged with liquid CO₂, a heating device vaporizes it in milliseconds, and the phase change expands the volume 600–1,000 times, generating 200–300 MPa before a rupture disc releases the gas along the borehole. The component set is equally standardized — fill valve, heating device, storage tube, sealing discs, rupture disc and discharge head. Invented in 1914 and commercialized by the UK’s Cardox company, the method was credited in the 1940s with roughly 25% of US underground coal output, around 2.8 million shots per year.
That physics is exactly what our systems use. There is no proprietary mystery in the principle: liquid CO₂, phase change, controlled release. What has changed is who can build it, and at what cost.
Where the economics diverge: imported chain vs factory-direct
A cartridge-type imported system reaches you through a distribution chain — and you re-purchase consumables shot after shot. Our buyers typically compare three cost layers before switching:
- System acquisition: factory-direct pricing — at a fraction of a comparable imported system’s landed budget.
- Per-shot consumables: a CO₂ refill plus a heating element, versus a new cartridge for every shot. On repeating cycles this gap compounds every day of operation.
- Support distance: spare parts, tube customization and on-site training come directly from the manufacturer — not through a distant supply chain.
For recurring rock breaking — quarry benches, tunnel faces, underground stops — the per-shot economy, not the brochure, decides the total cost.
Four products, two mechanisms — an honest map
Cardox’s current business spans five industries: cement plant cleaning, power-plant boiler ash, bulk-material silos, civil rock excavation, and mining & quarrying. One honest distinction comes first: only our liquid-CO₂ lines use the true phase-change mechanism of a Cardox® system. The gas-expansion tube below is a different, simpler chemistry — right for a different set of job constraints.
- DL-51 reusable tube — boiler ash & silo desilting (liquid CO₂). The direct match for power plants, cement plants and bulk-material terminals: clears boilers, economisers, silos, bins and hoppers. Reusable steel tube, custom OD and length per vessel.
- DL-108 reusable system — deep-hole rock breaking (liquid CO₂). For high-frequency quarry benches and underground stops where per-shot economics dominate over the project life.
- #90 disposable metal tube — true liquid CO₂, no recovery. For sites whose rules or permits require genuine liquid-CO₂ phase change, but where collecting and returning spent tubes is impractical: a single-use metal shell with the same phase-change mechanism.
- Disposable 32/40 mm gas-expansion tube — chemical powder, no CO₂ logistics. The expansion gas is generated by a chemical powder — the same chemistry family as the activator in our CO₂ systems — not by liquid-CO₂ phase change. The gas itself is still predominantly CO₂: the difference is the source, not the name. Zero initial equipment, zero refill station, nothing to recover. Best for small or temporary jobs such as gold mining and tunnel rounds; the trade-off is a higher average cost per cubic metre — you pay for convenience, not hardware. See the disposable tube product page →
Send your requirement and we will size the right line — including a free tube-layout drawing before you commit.
Certifications and honest differences
Our tubes carry CE marking, and the heating agent inside every activation device has been tested by the National Civil Explosives Quality Inspection & Testing Center (CNAS L1002, Nanjing University of Science and Technology): under GJB military test methods, impact, friction and flame sensitivity tests all returned a 0% ignition probability, and electrostatic spark tests returned 0 ignitions in 58 trials at up to 20 kV (report N26046NAB6). Twenty years of manufacturing, machines in 50+ countries and more than 1,000 documented projects stand behind the product line.
To be equally honest about the other side: Cardox® carries a UK heritage dating to 1914, decades of brand recognition and established references in cement cleaning and underwater work. If brand history is your deciding factor, that is a legitimate consideration. If your deciding factor is the same working principle at factory-direct economics, with customization and direct engineering support — that is exactly what we build.
One-to-one with Cardox’s five industries
- Cement plants: DL-51 clears preheater towers, cyclones, kilns, coolers and precalciners.
- Power plants & waste-to-energy: DL-51 clears boilers, economisers and silos — the three zones Cardox is used for worldwide.
- Bulk-material terminals: DL-51 for silos, bins, hoppers and storage vessels.
- Civils: disposable tubes or the DL-108 for trenching, shaft sinking, concrete demolition and underwater excavation in sensitive areas.
- Mining & quarrying: DL-108 for benches and underground stops; disposable tubes for boulder breaking and small gold or tunnel jobs.
The fastest way to settle the comparison is your own project: send the rock type, hole diameter and target fragmentation, and we will return a tube-layout drawing with a configured quotation — usually within 2 business days.
Quick FAQs on the Cardox® comparison
Is this page affiliated with Cardox?
No. This is an independent comparison published by ZD Rock Breaking (DL Mining Equipment Co., Ltd.). We are not affiliated with, endorsed by, or connected to Cardox or its owner. “Cardox®” is used only to identify the product category being compared.
Which ZD tube matches Cardox’s five industries?
Boiler-ash, cement and silo cleaning → the DL-51 reusable tube. Deep-hole and high-frequency rock breaking → the DL-108 system. Sites that must use true liquid CO₂ but will not recover tubes → the #90 disposable metal tube. Small or temporary jobs without CO₂ logistics (gold mining, tunnel rounds) → the disposable 32/40 mm gas-expansion tube.
How fast can we start?
Send your rock type, hole diameter and target fragmentation. We return a tube-layout drawing and a configured quotation — typically within 2 business days — with EXW/FOB/CIF shipping options and an on-site training plan.
Get an engineer’s answer
Share your rock type and production targets — concrete setup proposal within 24 hours.