Copper ore heap leaching of waste

The process of copper ore heap leaching is: heap leaching-extraction-electrowinning; full liquid circulation is implemented. These include heap leaching-extraction-raffinate water phase return heap leaching; saturated organic reverse extraction-back extraction (rich) liquid electrowinning, and electrowinning tail liquid returned to the stripping solution for two cycles. To date, leaching copper heap leaching agent are used as sulfuric acid, by oxidation of the copper sulphide ore or iron Thiobacillus ferric sulfate as an oxidant.

From the copper heap heap leaching process, it produces waste similar to that produced by acid uranium heap leaching; however, it has no harmful effects of radioactivity and therefore has less environmental hazards. Copper heap leaching of wastes to the environment contaminated wastewater heaviest; waste pollution of the environment, often with heavy metals from the heap and the effluent solution is an acidic solution ionic contamination environment; not the whole heap leaching copper It will produce a gas that is harmful to the environment. In summary, there are two wastes generated by copper heap heap leaching:

First, wastewater

The toxicity of wastewater is mainly reflected in the acidity of the wastewater itself, the heavy metal ions and arsenic produced by the reaction of the leaching agent with minerals and gangue, and the organic phase introduced during the extraction process.

Second, waste residue

It consists of two parts, one of which is acid-impregnated waste rock, and the other is the sludge produced by the neutralization process. When the copper sulfide ore heap is immersed, because a large amount of iron enters the leachate, the waste generated by the wastewater treatment is large in volume and difficult to handle; in areas with acid rain, the sewage is likely to cause secondary pollution.

From the side of the ship one or two suction pipes descend to the bottom of the seabed. On the end of the pipe a so-called trailing Drag Head is connected. This head is comparable to a large vacuum cleaner and is trailed along the seabed. In the head there are nozzles connected to a high pressure water installation that are capable of loosening the material on the seabed. Due to lower pressure in the pipe, the material will be sucked inward and discharged in the hopper.

The vessel should always have a positive speed over the ground. It is possible to regulate the density of the sucked substance. If the head is lowered, more material will be sucked but there is a greater possibility of damaging the installation because the material can get stuck inside the pipes. Once the mixture is loaded inside the hopper, the substance will sink and the water is discharged overboard, creating more room for extra substance. A trailing Suction Hopper Dredger is only capable to suck relatively loose substance because the steel teeth are not so big. Harder substances such as rock, or ironbased rock must be destroyed by a cutter.

Photo of our Suction Pipe:

Suction Pipe


The specifications of our suction pipe

A. General

High accuracy, fully welded, painted construction can be used for trailing suction hopper Dredger , suction pipe plays an important role. It is approved BV 

Suction pipe system ensure full control of the drag head on the bottom, transport the dredge mixture to the hopper, then transmit the trailing force from the drag head to the ship and support pipes and cabling.

B. Construction and procedure

The construction is to be built according to the drawing with rules of good workmanship and to be built the longitudinal frame system.

The construction consist big suction pipes, Turning Gland, joint, jet line, Seamless Pipes, supports for cable and hoses, which are carefully manufactured and checked to ensure total length, straightness, symmetry within the specific tolerances.

C. Procedure

Welding seam preparation-Pre roll bending of plate tip-Rolling-Longitudinal welding (SAW),inside then outside-Crossing welding (SAW) between part tubes to form the whole pipe-US testing and repairing-Adjusting-Assemble other part

D. Materials

All fabricated steelwork used in the construction of the suction pipe will be to manufacturing standard of classification society BV, GL, LR, DNV, especially for neck flange.

All steel used to be blasted and shop primed both sides. Using DH36

All materials proposed will be selected to comply with the latest Health and Safety Rules.

Paint systems for hull protection will be of the highest quality (Hempel, Inter, Sigma, Jotun)

E. Welding

All welding will be performed in accordance with drawing and order and UniSite experience and all welding will be continuous and full penetration.

Welding seam preparation, welding method, welding material and consequent preheating temperature acc. to UniSite standards and approved by clients.

F. Workmanship

The workmanship have good marine practice. Care are taken to ensure fair lines, smooth surfaces and neat welding.

G. Main particulars

 

MAIN PARTICULARS

Tolerance

High accuracy(ISO2768, ISO5817, ISO13920)

Material

Q345D, DH36 other materials

Dimension(L*B*H)

As per drawing, as large as we can

OD

1000mm-2000mm

Weight

15Ton~70Ton

Coating

Sa2.5 blasted and two or three layers painted with highest quality

Marking

as per clients' requirements

Inspection

material, construction, dimension, welding seam, non defective test, paint inspection

Experience

We made a whole suction system with length 49.3m for world top dredging company.

Others

Recyclable, in line with environmental requirements and standards, and reliable

 


Suction Pipe

Dredging Suction Pipes,Suction Tube,Suction Connecting Tube,Pipe Joint

Unisite Group Ltd. , https://www.unisitemarine.com