Impact of key parameters on the iron ore pellets roller screening performance

Abstract

The roller screening process is an important step in the iron ore pellets production. This step is intrinsically linked to the balling production and the induration machine. Improvements to the equipment performance not only promotes benefits to the plant’s productivity, but also in the final product’s quality. Several parameters influence the equipment’s performance, impacting directly or indirectly the screening ratio (ton/m2 of open screen area). The objective of this work is to provide information regarding the key parameters influencing the roller screening performance through practical expertise and literature review, due to the lack of studies related to this important equipment. It is a review manuscript describing the screen variables and its impact on the iron ore pelletizing process.

The impact of new technologies on the iron ore screening flowsheet

“…The roller screening process is probabilistic, influenced by various factors such as the movement of pellets, screen deck inclination, particle orientation, size distribution, shape, gap opening, and residence time on the screen. The efficiency of a roller screening process is significantly impacted by several key factors that influence the screening ratio (ton/m 2 ), the quantity of rolls, rolls' diameter, rolls' length, and the feed tonnage [21]. The number of rolls directly affects the screening ratio.…”

“…More rolls for the same feed tonnage result in a lower screening ratio, enhancing the screening surface area and improving the probability of particles reaching the gap opening for classification. However, a higher quantity of rolls can increase the plant footprint, leading to elevated capital expenditures (CAPEX) and operational costs (OPEX) [21]. Additionally, an excessive number of rolls may cause issues with pellet transportability, creating a "cigarette effect" where pellets get stuck, altering their shape and obstructing the screening gaps [21].…”

“…However, a higher quantity of rolls can increase the plant footprint, leading to elevated capital expenditures (CAPEX) and operational costs (OPEX) [21]. Additionally, an excessive number of rolls may cause issues with pellet transportability, creating a "cigarette effect" where pellets get stuck, altering their shape and obstructing the screening gaps [21].…”

An image fusion-based method for recovering the 3D shape of roll surface defects

“…Five fusion methods were also selected for comparison with the methods in this chapter, such as multiscale weighted gradient fusion (MWG), discrete cosine transform (DCT) based fusion, continuous ridge wave transform (Curvelet) based fusion, and NSCT-mPCNN fusion method and NSST-mPCNN fusion method. In this chapter, the number of decomposition directions of NSST is set to [4,4,3,3] and the non-downsampling pyramid is 'max flat'. m-PCNN parameters are set to, respectively α T = 0.012, σ = 1, V T = 4000, β = 0.1, ρ = 0.01, λ = 0.2, with a maximum number of iterations of 200, For the evaluation of fusion image quality, four objective evaluation parameters are chosen, namely information entropy (IE), standard deviation (STD), average grads (AG), and mutual information (MI), as shown in equations ( 17)- (20).…”

“…The precision and reliability of rolls are therefore becoming crucial [1,2]. Rolls play an important role in many industries such as steel production, printing, paper, and paper processing [3,4]. However, defects on the surface of rolls can lead to significant production losses and even * Authors to whom any correspondence should be addressed.…”