Bulk material handler (stacker-reclaimer)

01

Understand how a stacker-reclaimer works

Juli Engineering, a bulk handling equipment maker, describes its bucket-wheel stacker-reclaimer as a machine that can both stack and reclaim. When stacking, a tripper unloads material from the overland belt conveyor onto the conveyor on the boom, which discharges it from the boom end onto the stockyard; slewing and pitching the boom builds a pile with a trapezoidal section. When reclaiming, the boom slews while the bucket wheel rotates continuously, and the material runs back along the reversed boom conveyor and down through a funnel at the machine centre onto the overland conveyor. [1]

BVEE, another supplier, says stacker-reclaimers “normally travel on a rail between stockpiles in the stockyard”, and lists boom-pivot types that stack or reclaim on both sides of the feed conveyor through luffing and slewing movements. [3]

Juli lists further types for different yards: bucket-wheel stacker-reclaimers, bridge bucket-wheel reclaimers, portal and side scraper reclaimers, bridge scraper reclaimers, top-stacking lateral-reclaiming machines and circular-stockyard homogenising stacker-reclaimers. [2]

Give the supplier the material, lump size and bulk density, the stacking and reclaiming rates, the stockpile dimensions and yard layout, the rail span and length, the conveyor interfaces, the blending requirement, the power supply, the climate and the automation level required.

02

Size the capacity and choose the machine type

BVEE states that stacker-reclaimers are volumetric machines rated in m³/h, a figure “often converted to t/h” using the average bulk density of the material being reclaimed. Henan Zehua lists a stacker-reclaimer with a capacity of 3,000 t/h. [3] [4]

For ports, SANY lists excavator-type material handlers. Its SMHC160 has a 6 m working depth, 30 m working height, sticks of 22, 26 or 30 m, a Deutz D09S3T9 engine, 3 km/h travel speed and 5 r/min slewing speed. The wheeled SMHW40G5 lists a 16.5 m maximum operating radius. [5]

MMSTACKER lists mobile stacker conveyors, mobile hopper feeders, mobile bucket-wheel reclaimers and mobile material handlers for sites that need movable equipment instead of rail-mounted machines. [6]

03

Choose the stacking method and reclaimer for blending

A review of stacking and reclaiming methods by Charles G. Schofield in bulk solids handling (September 1981) treats the stockpile as a mixing device. In chevron stacking the stockpile is layered along a fixed axis by a stacker whose boom is adjustable in height to limit dust and free fall. Layer-by-layer stacking divides the input flow, and its quality variations, into small quantities per layer; increasing the number of layers reduces the material per layer, and Schofield writes that "in general this enhances the homogenisation effect of the stockpile". [7]

The paper notes that chevron stacking segregates larger particles towards the base of the pile. Where that variation must be minimised, it suggests windrow or windrow/chevron layering. Except for storage, it discounts the conical heap, because particle size segregation in a cone generates variation on reclaim rather than homogenising the material. [7]

For blending, it says the stockpile must be reclaimed from the front in cross-sectional slices, so that each slice is close to the pile's average quality. Side-acting, front-acting and bridge-type scrapers reclaim slice by slice in this way, while travelling scrapers that reclaim longitudinally limit the variability reduction obtainable. The bridge-mounted bucket-wheel reclaimer it describes traverses the pile end face, with harrows loosening the face and feeding material to the buckets at the base; the bridge advances by an adjustable increment after each traverse. [7]

Schofield describes bucket-wheel reclaimers as applied in cement and in iron and steel where homogenisation is the main requirement and the material is not sticky, and advises against underground paddle-wheel or plough reclaim because it lacks flexibility. [7]

As an ore-service example, TAKRAF lists a boom-type bucket-wheel reclaimer for iron ore at Vale's Brucutu site, commissioned in 2006, with a reclaim capacity of 9,200 t/h, a cell-less bucket wheel with hydraulic drive and automatic GPS positioning; two reclaimers of the same type share one rail track. [8]

Editorial calculation: at 9,200 t/h, a 100,000 t pile would take about 10.9 hours to reclaim at full rate (100,000 ÷ 9,200). The pile size is an assumed example; actual time depends on the average rate achieved over the face. [8]

Give the supplier the material and its bulk density, lump size and stickiness, stacking and reclaim rates in t/h, stockpile length, width, height and number of piles, blending requirement (input and output quality variation), stacking method, rail span and length, power supply, automation and positioning, dust control, and climate.

04

Stockyard machine data: type, rate, stacking method, rails and positioning

The stacking and reclaim rows come from Schofield's 1981 review; the capacity and positioning examples are maker figures from Zehua and TAKRAF.

05

Send the material, rate and yard data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Material: [type; lump size; bulk density]
Rates: [stacking t/h; reclaiming t/h]
Yard: [pile size; rail span; length]
Conveyors: [interfaces; belt width]
Functions: [stacking; reclaiming; blending; ship/truck]
Power and controls: [supply; automation]

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