Autoclave pilot plant

The autoclave pilot plant (APP) was commissioned in April 2011 and it’s located on the basis of the pilot plant of ore enrichment of Pokrovsky Rudnik OJSC (Blagoveshensk). APP is designed for pilot testing of autoclave processing of polymetallic raw materials (ores and concentrates) in a continious mode at temperatures up to 250 °С and total pressure up to 4,5 MPa.

Conditions for the autoclave process can differ in the following parameters:

  • The type of feed solution or atmosphere that occurs during the process.
  • The presence of oxidizing agents (oxygen, air) in the gas phase or the absence of supplied gases.

APP allows to carry out the following autoclave processes in continuous mode:

  • Oxidation of gold-beraing sulfide raw materials for the destruction of sulfides (pyrite, arsenopyrite, etc.), which prevent the extraction of precious metal.
  • Oxidation of polymetallic sulfide raw materials for the recovery (dissolving) of valuable components (copper, zinc, etc.).
  • Processing of oxidized ores with dissolving of the  valuable components (nickel, etc.).
  • Hydrothermal enrichment of copper sulfide concentrates in terms of copper due to the dissolving of other  components (zinc, iron and sulfur).

APP is equipped with modern equipment, allowing to carry out a number of hydrometallurgical operations:

  • Preparation of raw materials before feeding into the autoclave (grinding, acid treatment, washing, heat treatment (roasting), etc.).
  • Conditioning (heat treatment) of autoclave slurries to improve the quality of intermediate products.
  • Dewatering of autoclave slurries (thickening and filtration).
  • Neutralization of acidic autoclave solutions.
  • Neutralization and cyanidation of autoclave residues.

Autoclave

Autoclave
Specifications

  • Working volume: 35,4 l
  • Four sections, five agitators (in the first sections two of them)
  • Body material: titanium TA2
  • Working temperature: up to 250 °С
  • Working pressure: up to 4,5 Mpa
  • Rotation speed of agitators: 0-1500 min-1 
  • Body heaters power: 4 and 8 kW
  • Agitators drive power: 0,55 kW
  • Number of sampling vessels (one 500 ml and four 850 ml)

Autoclave control system

Operator’s workplace
  • Safe location of the operator workplace outside the autoclave room
  • Ability to control all equipment of the pilot plant
  • Visual assessment of the operation of the main equipment
Mnemonic diagram

Mnemonic diagram

  • Graphical display of main equipment
  • Color indicator of equipment operation
  • Managing the operation of the main units of the pilot plant
  • Recording and storage more than 40 technological parameters and perfomance indicators of equipment
  • Sound and color notification of emergency situations
(pos. 200) autoclave feeding containers

autoclave feeding containers

  • Number of reactors: 2
  • Reeactor volume: 200 l
  • Material: PP
  • Temperature: 20-95 °С
  • Agitator drive power: 0,55 kW
(pos. 201) Netzsch and Sydex screw pumps

Netzsch and Sydex screw pumps

  • Feeding of neutral and slightly acidic slurries
  • Working pressure up to 4.0 MPa
  • Solid content in the slurry up to 50-55%
Unit capasity
  • Netzsch 7-25l/h with solid content ~50%
  • Sydex 15-60l/h with solid content 55-60%
  • Working temperature  15-30 °С
  • Pump operation control according to the indicators of the Mag 5500 (Siemens) flow meter

(pos. 207) Slurry discharge

Discharge of oxidized slurry is carried out in a semi-continuous mode

  • Continuous accumulation of slurry in the vessel 207
  • Continuous control of slurry mass in vessel 207 by HBS-200l strain gauge
  • Periodic discharge of slurry portions (up to 8-10 l) into vessel 208 through valve 57
  • Feed of nitrogen or comperessed air to the vessel 208
  • Discharge of excess pressure through valves 87 and 88
  • Discharge of the 208 vessel through valve 58
  • Discharging in automatic mode
Discharge of off-gas

Discharge of off-gas

  • Continuous flow of off-gas form the autoclave vessel 207
  • Control of the amount of off-gas with and electronic rotameter ????
  • Control of the composition of off-gases with a GAMMA-100 gas analyzer (ranges: for O2 0-100% and CO2 0-12%)
Oxidizing gas feed to the autoclave

Oxidizing gas feed to the autoclave

  • Oxidizing agent- technical oxygen from cylinders (97-99%)
  • Gas feed for four agitators (sections?) 
  • Oxygen feed to liquid or gas phases
  • Gas flow control (Bronkhorst flow meters): 0,6-30 Nl/min (one device)
  • Maximum inlet pressure 5.0 MPa
Hot water dosing pumps intu the autoclave
  • Designed for feeding cooling water to the autoclave.
    Насосы-дозаторы острой воды в автоклав
  • Water flowrate up to 5, 30, 58 and 70 l/h
  • Maximum outlet pressure up to 6,3 and 10,0 MPa
  • Drive pover 0,25, 0,37 and 0,55 MPa
  • Cooling water temperature 10-95 °С
  • Availability of safety and non-return valves on pressure pipelines
 Ball mill

Шаровая мельница

  • Reactor volume 70 l
  • Solid load 25-30 kg
  • Rotation speed 30-60 min-1   
  • Drive power 0,55 kW
Acid treatment reactors

Hydrometallurgical operations (acid treatment, conditioning, etc.) with temperature control
Реакторы кислотной обработки

  • Number or reactors: 2
  • Reactor volume 200 l
  • Material: PP
  • Temperature 20-95 °С
  • Drive power 0,55 kW
Nutsche-filters

Нутч-фильтр

  • Number of nutsche-filters: 2
  • Filtration area 0,44 m2   
  • Body material: PP
  • Filter cloth: PET
  • Temperature 20-95 °С
 Larox press filter

Пресс-фильтр Larox

  • Bilateral filtration (1 chamber)
  • Filter area 0,3 m2  
  • Maximum pressure 1,6 MPa
  • Chamber thickness: 25, 40, 50 and 60 mm
  • Chamber volumes: 2,9, 4,8, 6,1 and 7,5 l
  • Reactor volume 100 l
  • Temperature 20-85 °С
Auxuliary equipment
Continuous neutralization plant

Study of neutralization of solutions in a continuous mode.
Установка непрерывной нейтрализации

  • Number of reactors: 5 (2 titanium and 3 stainless steel)
  • Reactor volume 25-30 l
  • Temperature 20-95 °С
  • Feed tank volume 450 l
  • Reagent feed to each reactor
  • Peristaltic pumps: Watson Marlow 0-400 ml/min
  • Oxygen feed to each reactor
  • Continuous pH control
Bottle agitator

Cyanidation of solid products in pereodic mode.
Бутылочный агитатор

  • Number of agitators: 3 (2 for 20 bottles and 1 for 10)
  • Rotation speed 20-60 min-1    
  • Volume of reactors (bottles) 750 ml
  • Air access