Emirates Global Aluminium (EGA) proprietary DX technology in Jebel Ali Line 8 has seen continuous amperage increase from 340 kA at start-up in 2008 to 440 kA today. Line 8 of 44 cells is at the end of Line 6 operating at 260 kA, therefore, at 440 kA, 180 kA has to be supplied by four Line 8 booster rectifiers, 45 kA per rectifier, at nameplate capacity. The booster rectifier station was designed in N-1 configuration with four rectifiers, three in operation and the fourth one on standby for maintenance, to keep line current constant. However, with large amperage increase from 340 kA to 440 kA since the start-up in 2008, when the amperage reached 400 kA 1n 2014, all four booster rectifiers have been used in routine operation. Consequently, during annual maintenance, taking 7 days per rectifier, and 28 days for four rectifiers, the potline operated at 35 to 45 kA below the normal amperage with the three booster rectifiers. This required changes in many cell operation and cell control parameters.

This paper describes the strategies and practices for rapid amperage decrease by 35-45 kA at the start of maintenance, and rapid increase to normal amperage at the end of maintenance. Now, the amperage is decreased in increase at the end of maintenance has been shortened from fourteen days to just two days in 2-3 steps, thus restoring normal metal output rapidly.

Seasonal ambient variation plays a key influence in defining the operational window of an aluminium reduction cell, which is mostly determined by potline thermal balance. Even though gas treatment plants often study these basic features of environmental changes separately, the parameters of the potline are related and must be addressed to have minimal effect. Thermal balance influences the pot current distribution, the dissolution of alumina, and the instability of the pot. Bath superheat is a key indicator of thermal balance in the potlines. The productivity and energy efficiency of the system are both ensured by keeping the superheat within a close range. Significant shifts in superheat can bring about unfavourable consequences, including an increase in the number of back reactions, the creation of sludge, and a decrease in the efficiency of the potline. Seasonal fluctuations also make cell operations more complex because of the impact of varying heat losses on thermal balance.

Sohar Aluminium LLC is a pioneering greenfield aluminium smelter and a market leader in Oman's manufacturing industry. To keep the thermal balance consistent throughout the year, regardless of the weather (summer-winter), this paper presents a predictive control method that adjusts the bath temperature set point, adds thermal resistance, and optimizes the pot forced cooling network (FCN) using real-time data or estimates of different indicators. This article delves into the seasonal routine and provides an insight into thermal balance management for changes in the context of Sohar Aluminium's experience.

In smelters Pot Tending Machines (PTM) execute a large number and complex activities, such as anode change, tapping operation etc. Each anode change is a sequence of tasks: breaking the crust, gauging, traveling, scooping, anode placement and more. For one standard smelter it represents more than half a million tasks to be executed correctly every year. To deliver production and ensure quality of aluminum, operations, and maintenance face various challenges. Two major factors are: a full compliance with operating standards and very regular and respected workflow. These two parameters have a direct impact on the efficiency of the aluminium production process and operation stability. As well as on its environmental impact and greenhouse gas emissions, since, for example, poorly managed work could lead to over-consumption of anode. SMARTCrane was implemented in various smelters and provided significant benefits for operations engineers and managers in taking proactive measures. Since it is running, it generated a vast amount of data and performance indicators. By analysing this data and deriving actionable insights, operation and process teams made informed decisions regarding, PTA availability, and compliance with operating procedures. After several years of industrial use, SMARTCrane captured and analysed worldwide more than 380 000 anode changes and made it possible to make a continuous control with loopback between the KPI measured with operations and maintenance.

In aluminum smelters, safety training is one of the first and foremost trainings delivered to the reduction staff. It generally covers risks associated with potline operational activities and risks related to electricity but, generally, it barely covers risks associated with pot process control. In the recent past, several of our customer smelters worldwide using ALPSYS reported significant incidents related, closely or remotely, to pot process control and/or their process control system. Those incidents were critical or potentially critical: open circuits, damage to pot equipment or very sick pots. Each incident has been thoroughly analyzed to identify root causes and mitigation actions and, in some cases, the control system has been modified to integrate mitigation actions. In most cases, the incident could have been avoided or its consequences greatly reduced, with a proper action from the plant staff. In rare cases, the incident was the direct result of a wrong action. In this paper, several real incidents are presented and discussed, and the lessons learned from those incidents are explained. These lessons learned are relevant for potlines controlled by any kind of control system, not only for potlines controlled by ALPSYS.