Henan Hongke Heavy Machinery Co., Ltd. has completed the delivery and commissioning of a Φ 2.5×45m zinc oxide (ZnO) rotary kiln production line for a customer in Tongren, Guizhou Province, China. This is a brand-new installation—not a refurbishment, not an upgrade of old equipment. Below is the full project breakdown: who the customer is, what problem they had, what we built, when it was delivered, and what the results were.
1. Customer Background
Location: Tongren, Guizhou Province, China
Industry: Non-ferrous metals / secondary zinc recovery
Tongren is located in northeastern Guizhou and is part of a mineral-rich region with significant zinc, manganese, and mercury deposits. The area has a long history of non-ferrous metal smelting and, more recently, a growing focus on secondary resource recovery—turning industrial residues and dust back into usable materials.
Our customer operates a zinc recovery facility in this region. They process zinc-bearing industrial residues, including steel mill dust and other byproducts, to recover zinc in the form of zinc oxide.
2. The Original Problem
Before approaching Henan Hongke Machinery, the customer was running an older production line with several unresolved issues:
| Problem | Impact |
|---|---|
| Inconsistent zinc recovery rate | Valuable zinc lost in slag; lower revenue per ton of feed |
| Unstable kiln temperature profile | Incomplete reduction; variable product quality |
| Frequent ring formation | Material sticking to kiln walls; unplanned downtime |
| High fuel consumption | Rising operating costs per ton of ZnO produced |
| Dust and emission control gaps | Difficulty meeting tightening environmental standards |
| Limited throughput | Unable to accept larger volumes of feedstock |
The customer needed a new, purpose-built line—not a patch-up of the old system. Their goal was straightforward: higher zinc recovery, consistent product quality, lower operating costs, and reliable 24/7 operation.
3. Why the Customer Chose Henan Hongke Machinery
After evaluating several suppliers, the customer selected us for specific, practical reasons:
a) Process understanding, not just equipment supply
Zinc oxide recovery via the Waelz process depends on the interaction of feed preparation, reduction temperature, kiln atmosphere, and gas handling. We discussed these parameters in detail during technical exchange—not just dimensions and price.
b) Custom design for their actual feed material
The customer's feedstock was not a standard zinc ore. It was a mix of industrial residues with variable zinc content and particle size. Our engineering team designed the kiln around those specific characteristics.
c) Complete line responsibility
We supplied the full scope: feed preparation equipment, the rotary kiln, burner system, oxidation settling chamber, cooling system, bag filter, slag quench system, and PLC controls. The customer did not have to coordinate multiple suppliers.
d) Brand-new equipment
The customer explicitly wanted a new system built for this application—not refurbished equipment and not a repurposed cement kiln.
e) Verified references and factory inspection
The customer reviewed our manufacturing facility and similar kiln projects before signing.
4. Equipment Configuration
The delivered line is built around a Φ 2.5×45m rotary kiln.
| Parameter | Specification |
|---|---|
| Kiln diameter | 2.5 m |
| Kiln length | 45 m |
| Application | Zinc oxide recovery from zinc-bearing residues |
| Kiln slope | 3–4% |
| Rotation speed | Variable frequency drive |
| Operating temperature | Up to 1,100–1,200°C (reduction zone) |
| Drive system | Heavy-duty gear drive with main and auxiliary motors |
| Sealing | Labyrinth seals with air purge at head and tail |
Scope of supply:
| System | Function |
|---|---|
| Feed preparation | Crushing, mixing with carbon reductant, pelletizing |
| Φ 2.5×45m rotary kiln | Reduction and volatilization of zinc |
| Multi-channel burner | Heat input, flame control |
| Oxidation settling chamber | Controlled re-oxidation of zinc vapor to ZnO |
| Surface cooling system | Gas cooling ahead of filtration |
| Pulse-jet bag filter | ZnO fume collection |
| Slag quench system | Slag cooling and discharge |
| PLC control system | Temperature, feed rate, speed, and emission monitoring |
5. Delivery Timeline
| Stage | Status |
|---|---|
| Technical exchange and process design | Completed |
| Manufacturing at Henan Hongke facility | Completed |
| Factory assembly and no-load testing | Completed |
| Shipment to Tongren, Guizhou | Completed |
| On-site installation | Completed |
| Commissioning and hot testing | Completed |
| Handover to customer | Completed |
The line has been delivered and handed over to the customer's production team.
6. Commissioning Results
| Performance Metric | Result |
|---|---|
| Zinc recovery rate | Improved compared to the previous line |
| Product quality | Consistent ZnO grade, meeting customer specifications |
| Temperature control | Stable reduction zone temperature across operating shifts |
| Ring formation | Reduced; fewer unplanned stoppages |
| Throughput | Meets the agreed design capacity |
| Emission control | Dust emissions within regulatory limits |
| Operating stability | Continuous operation achieved |
7. Customer Feedback
"The kiln has been running steadily since commissioning. The recovery rate is better than our old line, and the product quality is consistent. The engineering team was responsive during installation and commissioning. We are satisfied with the equipment and the support." — Production Manager, Tongren zinc recovery facility
8. What This Means for the Customer
| Benefit | Practical Value |
|---|---|
| Higher zinc recovery | More saleable ZnO per ton of feed |
| Consistent product quality | Stable offtake agreements with buyers |
| Lower fuel consumption | Reduced cost per ton |
| Less ring formation | Fewer unplanned stoppages |
| Environmental compliance | Meets local emission requirements |
| Full-scope supplier | Single point of responsibility |
9. Building Long-Term Partnerships
Our commitment to the Tongren customer does not end at handover. We continue to provide:
Technical support on process optimization
Spare parts availability for critical components
Maintenance guidance and preventive maintenance planning
Support for future capacity expansion or process adjustment
We view this delivery as the start of a long-term working relationship, not a one-time transaction.
About Henan Hongke Heavy Machinery Co., Ltd.
Henan Hongke Heavy Machinery Co., Ltd. (Henan Hongke Machinery) has been designing and manufacturing industrial processing equipment since 2006. Our product portfolio includes:
Rotary Kilns – for zinc oxide, lime, dolomite, molybdenum, metallurgy, and mineral calcination
Rotary Dryers – for sludge, sand, gypsum, biomass, and industrial materials
Ball Mills – for ore, slag, cement, and chemical grinding
Crushers – for primary and secondary size reduction
We focus on one-stop solutions for mining and materials processing—complete systems, not just individual machines. From engineering to installation and after-sales service, we stay with our customers every step of the way.
Let's Talk About Your Zinc Recovery Project
If you are processing zinc-bearing residues, steel mill dust, or similar feed materials, we can discuss kiln sizing, process configuration, and expected recovery performance based on your actual material.
Contact Henan Hongke Heavy Machinery Co., Ltd. — we will review your material data and propose a configuration that fits your production targets.
Henan Hongke Heavy Machinery Co., Ltd.
Rotary Kilns | Rotary Dryers | Ball Mills | Crushers – Built for Reliability, Backed by Service