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BR-102024018220-A2 - DEVICE FOR SIMULATING PRESSURE WEATHERING IN AGGLOMERATED AND GRANULED ORE AND TAILINGS

BR102024018220A2BR 102024018220 A2BR102024018220 A2BR 102024018220A2BR-102024018220-A2

Abstract

This invention focuses on the development of equipment for evaluating pressure weathering of ore and/or tailings aggregates or granules. Weathering, caused by external agents, can degrade these aggregates, resulting in a loss of mechanical properties. The study aims to develop equipment capable of simulating the stacking conditions, weather exposure, and water application, essential for understanding and mitigating the effects of weathering. Planned experiments were conducted, varying the applied force, water temperature, water flow rate, and test time to validate the technology. The results showed that the different test variations evaluated have a distinct impact on the strength of the aggregates, demonstrating that these factors play a significant role in the degradation of the aggregates and indicating the need to understand the mechanisms of weathering action on the physical properties of the aggregates and the correlation of the results obtained with the degradation observed on an industrial scale.

Inventors

  • FABRICIO VILELA PARREIRA
  • FELIPE VIANA PIMENTA
  • FLÁVIO DE CASTRO DUTRA
  • VALDIRENE GONZAGA DE RESENDE
  • ERIC AUGUSTIN
  • FRANCISCO JUNIOR BATISTA PEDROSA
  • SANDRA LÚCIA DE MORAES
  • ANDRÉ LUIZ NUNIS DA SILVA
  • LUIZ PAULO BERTOLDO
  • TAYNÁ CUNHA SOUZA

Assignees

  • VALE S.A.

Dates

Publication Date
20260317
Application Date
20240904

Claims (1)

  1. 1. Device for simulating pressure weathering in agglomerates and granules of ore and tailings characterized in that it comprises a cylinder with holes in the bottom (1) where the agglomerates or granules are placed, with a perforated plunger (2) where a controlled force is applied through a piston (3) and a water injection system with controlled temperature (4) and a water outlet pipe (5), inside a larger cylinder that keeps the whole system submerged in water (6); and an automation and operation control system (7).

Description

Field of invention [0001] The present invention is in the field of evaluating pressure weathering for agglomerates or granules of ore and/or tailings. [0002] More specifically, the present invention is in the field of equipment capable of simulating the conditions of stacking, exposure to weather and application of water, essential for understanding and mitigating the effects of weathering. State of the art [0003] Steel production chain reduction reactors require materials with a particle size that allows gases to permeate the charge, access the oxides, and thus perform the reduction. In this context, the permeability and particle size of the granules are extremely important for the production process. Iron ore granules, with particle sizes ranging from 30 to 6.3 mm, meet this requirement; however, with the depletion of ore sources, comminution and concentration of poorer ores have become more common, making agglomeration steps such as sintering, briquetting, and pelletizing necessary (Moraes SL de, Lima JRB de, Ribeiro TR, 2018). [0004] For the steel chain, the production of iron ore with adequate particle size is therefore a crucial factor for productivity, so both natural materials and agglomerates need to withstand the stresses caused by the transport and handling to which these products are subjected and the climatic conditions to which they are subjected during this process, resisting falls, compression stresses, abrasion, weathering effects and temperatures (Pedrosa, F.J.B. et. al., 2023). [0005] Thus, as important as the formation of agglomerates is the maintenance of these characteristics from their formation until the moment of their use. Without the occurrence of breakages and degradations that could harm the production processes of the steel chain. Among the main causes of degradation we can list thermal shocks, weathering, leaching caused by long periods of exposure to water and the mechanical stresses of handling and transport (Fonseca, V. O., 2003). [0006] Weathering is a process caused by the action of external agents that results in the degradation and decomposition of rocks, being influenced by two factors: the composition of the rocks and the natural agents that act in the environment (Azevedo, Antonio Carlos de. Dalmolin, Ricardo S. Diniz, 2006). [0007] Just like rocks, aggregates also suffer from degradation and decomposition caused by external agents, their chemical composition is altered by natural environmental conditions and/or by human action, as well as by the mechanical stresses involved in logistical operations of storage and transport (Fonseca, V. O., 2003). [0008] During the life of particleboard, the conditions to which it is subjected and the handling stresses end up degrading the particleboard, generating losses of mechanical resistance and the generation of fines through compression and abrasion fracture mechanisms (Peirce, T. J., A. E. Horton, and J. Tucker, 1980). Therefore, the evaluation of the mechanisms involved is of great importance for improving the quality of existing particleboard and for the development of new particleboard. [0009] There is also the problem of particulate emissions, as degradation causes the generation of fines that are eventually carried and dispersed by the wind, generating unwanted impacts. The main way to combat and reduce particulate emissions is the use of sprays with water or reagents dispersed in water (Halt, Joseph A., et al., 2015), which causes the agglomerates to be subjected to moisture, leading to degradation and the generation of new fines. Objectives of the invention [0010] The present invention aims to develop equipment to simulate the conditions of stacking, exposure to climate and application of water in agglomerates and/or granules, making it possible to understand and mitigate the effects of weathering in agglomerates or granules of ore and/or tailings. Brief description of the invention [0011] The present invention discloses a device for simulating weathering characterized in that it comprises a cylinder with holes in the bottom where agglomerates or granules are placed, with a perforated piston where a controlled force is applied and a water injection system with controlled temperature and a water outlet pipe, inside a larger cylinder that keeps the whole system submerged in water; the perforated piston being configured to press the agglomerates. Brief description of the figures [0012] Figure 1 reveals an embodiment of a weathering simulation device as defined by the present invention. Detailed description of the invention [0013] The main stresses that agglomerates and granules are subjected to are: the pressure resulting from stacking, the ambient temperature, the heating caused by exposure to the sun, the presence of water both from its application in the process to contain the emission of particulates and from the presence of rain, the drainage condition of the pile and the storage site causing them to become saturated