Recent developments in the application of kraft pulping alkaline chemicals for lignocellulosic pretreatment: Potential beneficiation of green liquor dregs waste

The accumulation of nonprocess elements in the recovery cycle is a common problem for kraft pulp mills trying to reduce their water closure or to utilize biofuels in their lime kiln. Nonprocess elements such as magne-sium (Mg), manganese (Mn), silicon (Si), aluminum (Al), and phosphorus (P) enter the recovery cycle via wood, make-up chemicals, lime rock, biofuels, and process water. The main purge point for these elements is green liquor dregs and lime mud. If not purged, these elements can cause operational problems for the mill. Phosphorus reacts with calcium oxide (CaO) in the lime during slaking; as a result, part of the lime is unavailable for slaking reactions. The first part of this project, through laboratory work, identified rhenanite (NaCa(PO4)) as the form of P in the lime cycle and showed the negative effect of P on the availability of the lime. The second part of this project involved field studies and performing a mass balance for P at a Canadian kraft pulp mill.

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Hemicellulose Extraction from South African Eucalyptus grandis using Green Liquor and its Impact on Kraft Pulping Efficiency and Paper Making Properties

BioResources ◽

10.15376/biores.8.3.3490-3504 ◽

2013 ◽

Vol 8 (3) ◽

Cited By ~ 3

Author(s):

Jonas Johakimu ◽

Jerome Andrew

Keyword(s):

South African ◽

Eucalyptus Grandis ◽

Kraft Pulping ◽

Green Liquor ◽

Paper Making

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A Review of Technologies Used in Handling The Acid Mine Drainage Challenge: Perspectives on Using Green Liquor Dregs As a Sustainable Option For Treatment of Acid Mine Drainage

The Journal of Solid Waste Technology and Management ◽

10.5276/jswtm/2021.1 ◽

2021 ◽

Vol 47 (1) ◽

pp. 1-18

Author(s):

Keolebogile R. Sebogodi ◽

Jonas K. Johakimu ◽

B. Bruce Sithole

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Current Trend ◽

Dissolved Metals ◽

Green Liquor ◽

Acid Mine ◽

Treatment And Prevention ◽

Green Liquor Dregs ◽

High Concentrations ◽

By Products

Acid mine drainage (AMD) is one of the repercussions that result from earth-moving activities around the sulfide-bearing mineral hosts. The detrimental effects associated with this AMD are driven by its characteristics, which include low pH and high concentrations of sulfate and toxic dissolved metals. Traditionally, the prevention and treatment of AMD are achieved by using technologies that use, amongst other, naturally occurring soils and carbonates. However, the continual use of these materials may eventually lead to their depletion. On the other hand, industrial by-products have been proven to occupying land that could have otherwise been used for profitable businesses. Additionally, the handling and maintenance of landfills are costly. In this current trend of a circular economy that is driven by industrial symbiosis, scientists are concerned with valorizing industrial by-products. One such by-product is the green liquor dregs (GLD) from Kraft mills. The neutralizing and geotechnical properties of these wastes have prompted the research pioneers to seek their potential use in handling the challenges associated with AMD. In this review, the formation AMD, trends in technologies for treatment and prevention of AMD are critically analyzed. This includes the feasibility of using GLD as an alternative, promising sustainable material.

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