Bayer Plant Research Articles

WuXi Biologics to buy a Bayer facility

WuXi Biologics will purchase a Bayer plant for finished biologic drugs in Leverkusen, Germany. In addition to being used by the Chinese pharmaceutical services firm, the plant will be a backup site for making Bayer’s Kovaltry, a recombinant antihemophilic factor. From its base in China, WuXi Biologics has expanded rapidly in recent years. It is building a $60 million biologics plant in Worcester, Massachusetts, and a $390 million facility in Dundalk, Ireland.

Famar buys Bayer plant in Quebec

Famar Health Care Services, a Greek custom manufacturer with 11 facilities in the European Union, is establishing a foothold in North America with the acquisition of a Bayer plant in Pointe-Claire, Quebec. The facility makes liquid-, semisolid-, and solid-dosage-form drugs and employs about 150 people. Last year, Famar acquired a Roche dosage-form drug plant in Spain.

Desilication of hematite, goethite and iron powder seeded low alumina to caustic liquors

Even though many studies have been carried out aimed at the development of methodologies for the inhibition of scale formation during the Bayer process there is still limited understanding of the underlying desilication processes and kinetics, in particular for the high solids density environment of single-stream heat exchangers. Our objective was to gain insight into the relative desilication due to nucleation and/or growth, and the kinetics of scale formation in the presence of typical solid phases. We have chosen a caustic aluminosilicate liquor composition in which both aluminate concentration and A/C are less than for heat exchanger feed liquor and hence aluminosilicate supersaturation is increased. These concentration conditions were chosen to investigate the early stage of scale formation in single-stream Bayer plant heat exchangers by increasing the component of aluminosilicate bulk precipitate upon seeding and decreasing the relative degree of scaling. The precipitation of aluminosilicate phases from this liquor at 140 and 180°C seeded with hematite, goethite and iron powder crystals was investigated. Upon seeding rapid desilication took place with significant suppression of scale formation on steel coupon surfaces as compared to unseeded experiments. Seeding with hematite resulted in the most rapid reduction in aluminosilicate supersaturation. Additionally, the presence of hematite, in contrast to the other seed types, appears to promote the transformation of sodalite to cancrinite. Precipitation was found to occur predominantly via heterogeneous nucleation during the 240min reaction time. The results of this study suggest that a seeding strategy, especially using hematite, may be effective in reducing scale formation on mild steel process equipment in a single-stream Bayer heat exchanger process environment.

Mechanism and kinetics of gibbsite-seeded sodium aluminosilicate crystallisation from synthetic spent Bayer liquor

Despite a significant number of studies having been carried aimed at developing strategies for scale inhibition during the Bayer process, particularly in heat exchanger systems, there is still limited understanding of the underlying mechanisms and kinetics of scaling, in particular for single stream plants. The aim of this study was to further this understanding for sodium aluminosilicate crystallisation in spent Bayer liquor seeded with gibbsite. Gibbsite is present in pre-desilicated bauxite which is mixed with spent liquor and then passes through the heat exchanger system in single stream Bayer plant circuits.The solution desilication rate, at 140°C, was found to increase significantly with increasing seed loading (or surface area) from 45gL−1 to 90gL−1 even though partial, and in some cases complete, dissolution of the gibbsite seed resulted in increased liquor Si solubility. SEM, particle size distribution and X-ray diffraction analysis of the solid residues demonstrated that heterogeneous nucleation and growth of sodalite on the gibbsite seed results in reduced scaling on steel coupon surfaces as compared to without seeding. These findings suggest that the gibbsite, inherent in pre-desilicated bauxite, may be effective in reducing scale on heat exchanger surfaces in a single stream process environment.

Characterisation of single-stream Bayer plant heat exchanger scale

During the Bayer process, deleterious scale formation, consisting largely of aluminosilicate and titanate phases, results in additional consumption of caustic soda and decreased heat transfer efficiency thereby increasing energy costs. However, little characterisation has been undertaken as to the nature of these scales, particularly from within single stream Bayer refineries. Five contrasting scale samples have been studied using SEM, EDS, XRD Rietveld analysis, and for three samples synchrotron XANES analysis. Cancrinite, perovskite or katoite were found as major crystalline phases in these scales; however, a significant amorphous content was also found to be present. In conjunction with XRD and EDS analyses, Al K-edges XANES linear combination analysis indicates that the amorphous component in the scale samples consists predominantly of poorly crystallised sodalite. Relatively minor components of hematite, found in all scales samples, and boehmite, found in some scales were distributed homogenously. It appears that scale formation in single stream heat exchangers occurs via a mixed mechanism: precipitation of aluminosilicate phases, including amorphous components, and also on occasion katoite (Ca3Al2(OH)12) and perovskite (CaTiO3) from the Bayer liquor plus cementation of pre-desilicated bauxite phases, e.g. DSP, hematite and boehmite from the slurry onto heat exchanger steel surfaces.

Production of micro-crystalline boehmite from hydrothermal processing of Bayer plant alumina tri-hydrate

Abstract Plant alumina trihydrate (ATH, Al(OH) 3 ) from Korea Alumina (KC) Ltd's Bayer alumina plant was used to synthesize boehmite, a new product used as fire retarding fillers or laminating materials. The hydrothermal treatment conditions were optimized from tests conducted with ATH-water slurries (30, 40 and 50 w/v%) at different temperatures (160–220 °C), reaction time (10–80 min) and mean feed sizes D 50 (1.5–50 μm). Well crystalline boehmite was formed at a temperature > 200 °C after 60-minute treatment. The reaction pressure (1.0–2.0 MPa) has no effect on the process. The hexagonal crystal of the starting gibbsite changes to plate-like shape as boehmite is formed. After the treatment, the boehmite mean particle size (4–25 μm) is generally smaller than the original gibbsite feed (8–50 μm). For finer ATH feed (1.5–2.5 μm) there is no change in particle size after the hydrothermal treatment. The highly crystalline boehmite product containing 2 O and 2 O 3 has higher purity and whiteness than the ATH feed.

BAYER ACCUSED OF SKIRTING SAFETY

A DECISION TO HASTEN the restart of a pesticide production process and bypass safety controls led to a tragic accident on Aug. 28, 2008, at the Bayer CropScience plant in Institute, W.Va., concludes the Chemical Safety & Hazard Investigation Board (CSB), in a report released on Jan. 20. The accident destroyed a key pesticide manufacturing unit, killed two workers, required 40,000 people living near the plant to shelter in place, and revealed gross inadequacies in Bayer’s accident emergency response operations. Workers at the Bayer plant were under pressure to resume production of the pesticides methomyl and Larvin after a lengthy maintenance shutdown, according to the CSB investigation. As a result, they failed to evaluate new computer programs, inspect safety equipment, and conduct safety process checks. Most critical, the report says, was the intentional overriding of an interlock system that was designed to prevent a runaway reaction inside a residue treater pressure vessel. Late at ...

Precipitation of fine aluminium hydroxide from Bayer liquors

The precipitation of fine aluminium hydroxide (Al(OH) 3) powders (average particle size < 2 μm) from Bayer plant liquor was investigated, which is important for the production of specialty alumina (Al 2O 3) products. The process involves first a nucleation stage to form primary seeds by adding an acidic aluminium sulphate solution to a Bayer plant liquor which contains 210 g/L caustic (assayed as Na 2CO 3) and an alumina/caustic ratio (A/C) of 0.65. Further addition of the plant pregnant liquor to this primary seed slurry produced secondary gibbsite seeds required for the precipitation of high quality fine aluminium hydroxide powder. The precipitation was controlled at 50–60 °C using 0.5–1.0% w/w secondary seed addition with respect to the alumina content in the pregnant liquor.

Leaching behaviour of a Bayer electrofilter fines in sulphuric acid

Sulphuric acid leaching of electrofilter fines Bayer Plant was investigated at different temperatures, using various particle size fractions and acid concentrations. Results showed that extraction was affected by acid concentration, initial particle size fraction and temperature of leaching. Aluminium dissolution in sulphuric acid increases as temperature does. At 90 °C, the increase in both acid concentration and reaction time has a positive effect on the extraction rate, which is also favoured by the decrease in particle size and solid:liquid ratio. The results of a leaching kinetic study are presented. Heterogeneity of the residue implies the existence of two different kinetics, the first one fundamentally due to the dissolution of the hydrate and the second one, being the case in study, due to the dissolution of transition alumina. The data obtained for the leaching kinetics in this second case, indicated that the dissolution of aluminium is a diffusion controlled reaction.

Nutrient status of vegetation grown in alkaline bauxite processing residue amended with gypsum and thermally dried sewage sludge - A two year field study

Although the treatments for overcoming the high pH and exchangeable sodium percentage (ESP) of bauxite residue are well known, there is little information on long-term nutrient management of vegetation after rehabilitation. The present study examined the chemical and physical amendment of fine fraction residue (red mud) at the Aughinish Alumina Ltd. Bayer Plant, Ireland followed by a two-year field investigation. Gypsum and sewage sludge were incorporated into the residue and amended mud sown with Lolium perenne and Holcus lanatus. Aerial portions were harvested and nutrient composition determined annually for the first two years growth. Amended substrate was low in manganese and magnesium. After year one herbage contained adequate calcium levels, but there were deficiencies for nitrogen, manganese, potassium and magnesium. Sodium levels were not considered excessive and levels declined further in year two. Levels for nitrogen, calcium, manganese, magnesium, phosphorous and potassium were also reduced in the second year. As levels were already deficient in year one the further decreases suggest severe nutrient shortage in the residue substrate. For long-term success of revegetation of bauxite residue, even after gypsum and organic amendment, the deficiencies of nutrients in the substrate must be overcome.

Aspects of electrochemical behaviour of carbon steel in different Bayer plant solutions

Cyclic voltammetric and potentiodynamic studies were carried out on 300W carbon steel in Bayer plant solution, at 100 °C, with different alumina concentrations. Alumina behaves as an anodic inhibitor, shifting the critical passivation potentials positively and decreasing the critical passivation current with increasing concentration. Increase in alumina concentration promotes the formation of a uniform and less porous film. The pore resistance model describes the properties of the oxide films. Aluminium was found in all oxides formed, supporting the formation of a mixed oxide Fe3−xAlxO4. Thermodynamic calculation of some equilibrium potentials was carried out using the Fe(OH)3− ion rather than HFeO2− ion. Moreover, the Al(OH)4− ion was considered instead of AlO2− ion in the oxidation process.

The solubility of sodalite and cancrinite in synthetic spent Bayer liquor

The equilibrium SiO 2 solubility of sodalite and cancrinite crystals in sodium aluminate solutions containing low concentrations of aluminium (synthetic spent Bayer liquor) has been determined over a range of temperatures (90–220°C) and as a function of solution NaOH and Al(OH) 3 concentration for cancrinite. The same SiO 2 solubilities, within experimental error, were measured when equilibrium was approached from both above and below SiO 2 solubility for spent Bayer liquors in contact with either sodalite or cancrinite crystals. The solubility of sodalite and cancrinite (expressed in terms of SiO 2 concentration) increased linearly with increasing temperature. The equilibrium SiO 2 solubility of sodalite was higher than that of cancrinite at all temperatures. The solubility of cancrinite increased with increasing concentration of NaOH (3.87–5.42 M) and Al(OH) 3 (1.39–2.23 M) in solution. The SiO 2 solubilities of four types of dimorphic sodalite/cancrinite mixed phase seed crystals synthesised from Bayer plant spent liquor and synthetic Na 2CO 3, Na 2SO 4 or NaNO 3 rich NaOH solutions containing dissolved kaolinite were investigated. The solubility of the four types of mixed phase seed crystals was found to be substantially the same as the solubility for pure cancrinite.

99/03133 Rare earth promoted nickel catalysts for the selective oxidation of natural gas to syngas

Sulphuric acid leaching of electrofilter fines Bayer Plant was investigated at different temperatures, using various particle size fractions and acid concentrations. Results showed that extraction was affected by acid concentration, initial particle size fraction and temperature of leaching. Aluminium dissolution in sulphuric acid increases as temperature does. At 90 °C, the increase in both acid concentration and reaction time has a positive effect on the extraction rate, which is also favoured by the decrease in particle size and solid:liquid ratio.The results of a leaching kinetic study are presented. Heterogeneity of the residue implies the existence of two different kinetics, the first one fundamentally due to the dissolution of the hydrate and the second one, being the case in study, due to the dissolution of transition alumina. The data obtained for the leaching kinetics in this second case, indicated that the dissolution of aluminium is a diffusion controlled reaction.

Influence of environmental variables on erosion-corrosion of carbon steel in spent liquor reheaters in Bayer plant

Influence of environmental variables on erosion-corrosion of carbon steel in spent liquor reheaters in Bayer plant

Influence of environmental variables on erosion-corrosion of carbon steel in spent liquor reheaters in Bayer plant

The present work studied the factors involved in service erosion-corrosion of mild steel in spent liquor reheaters in Bayer plant. The impinging jet test rig was used to study the influence of (1) Bayer liquor composition, (2) nature of local flow, particularly recirculating flow, (3) nature and concentration of atmospheric gases (such as oxygen) in the liquor, and (4) quantity and nature of two phase flow, (including liquid + vapour and liquid + particulates). Low damage rates were associated with all conditions of single phase liquid flow. There was damage for experiments in which atmospheric gasses (O 2 and N 2) were present; the experiments indicated that at 70°C the impact of gas bubbles were responsible for much of the damage, whereas at 80°C there was a significantly greater role for the chemical action of oxygen. There was no significant damage for particle loading typical of service. High damage rates can be associated with two-phase liquid-vapour flow; more controlled experiments are necessary to understand the parameters controlling such damage.

A new impinging jet test rig used to identify the important parameters in service erosion-corrosion in bayer liquor and to study the damage morphology

An impinging jet test rig (IJTR) was designed and constructed to study the mechanism of erosion-corrosion in high temperature caustic solutions and was used in a systematic program of experiments at the Bayer plant site. Although there was a particulate loading in the liquor, no significant erosion-corrosion effect could be attributed to the presence of these particulates. Low damage rates were observed for all cases of a submerged liquid jet under controlled conditions of one-phase flow; for example, the damage rate was 0.04 mm year −1 at a jet velocity of 30 m s −1 at 150 °C. Using liquor with a higher source temperature, higher damage rates of 0.4–4 mm year −1 were measured. These higher damage rates are tentatively attributed to the inevitable two-phase flow at the start and end of these tests. There was a significant damage rate of 40 mm year −1 in one test using liquor with a higher source temperature. The damaged region showed flow-induced damage patterns with a facet type of surface morphology. Careful analysis of test conditions led to hypotheses concerning conditions leading to high damage rates.

Multi-variable Identification and Optimal Control for Bauxite Digestion

In this paper the design of a controller for the bauxite digestion section of an alumina Bayer plant is discussed. A linearised multiple input, single output (MISO) model of the process, consisting of discrete z-transform transfer functions, is proposed. The coefficients of the model are estimated from plant data by the application of an identification technique based on an instrumental variable (IV) approach. The models so obtained have been applied in the design of an optimal controller. The performance of this controller has been evaluated by simulation.The control scheme includes an optimal feedback element for the control input (bauxite ore feed rate) and feedforward elements for the remaining non-controllable inputs (spent liquor return flows). A pure time-delay of approximately ten minutes is encountered, thus giving a considerable time lag before the effects of an input feed rate change are seen at the output (the caustic to alumina concentration ratio).In the Bayer process effective control is particularly important because digestion stabilisation means increased production by increasing the output target ratio closer to the limit of extraction for the plant. By implementing the proposed optimal controller greater than 50% improvement in the variance of the controlled ratio output may be expected.

Some Properties of Bayer Plant Waste "Red Mud"

Some Properties of Bayer Plant Waste "Red Mud"