GB 50986-2014Code for design of dry red mud stack (English PDF)

2.0.1 red mud

The waste residue produced after alumina or aluminium hydroxide has been extracted from aluminium-bearing mineral raw materials.

2.0.2 water ratio of red mud

The ratio of the mass of water lost by a red mud specimen when dried at 105 °C to 110 °C to constant weight to the mass of the red mud after constant weight has been reached, expressed as a percentage.

2.0.3 dry red mud

Red mud whose liquidity index is less than 0.75 after sun-drying or mechanical dewatering treatment.

2.0.4 red mud yard

The site used to store the red mud discharged during the production process of alumina or aluminium hydroxide production enterprises.

2.0.5 dry red mud stack

A red mud yard adopting the dry stocking process of paste or the dry stocking process of filter cake.

2.0.6 dry stocking process of paste

A red mud stocking process in which red mud paste with a water ratio greater than the liquid limit and less than 150% is conveyed by pipeline to the red mud yard, where distribution, sun-drying, turning and sun-drying, rolling compaction and dam construction operations are carried out.

2.0.7 dry stocking process of filter cake

A red mud stocking process in which red mud slurry is filtered by a filter into a filter cake with a water ratio less than the liquid limit, and the filter cake is then transported by belt conveyor or motor vehicle to the red mud yard, where spreading, sun-drying and rolling compaction operations are carried out.

2.0.8 dry red mud stack of paste

A red mud yard adopting the dry stocking process of paste.

2.0.9 dry red mud stack of filter cake

A red mud yard adopting the dry stocking process of filter cake.

2.0.10 red mud dam

A structure in a red mud storage yard used to retain red mud slurry or red mud filter cake; it generally refers to the whole consisting of the starter dam and the embankment of the red mud storage yard.

2.0.11 starter dam

A dam built of earth, rock or other materials that serves as the supporting body of the red mud embankment.

2.0.12 embankment

A dam formed by the accumulation of red mud during the production process.

2.0.13 damming way of upstream red mud

A damming method in which red mud is accumulated in the upstream direction of the starter dam.

2.0.14 height of red mud dam

The difference in elevation between the crest of the embankment and the original ground surface at the axis of the starter dam. For a filter-cake dry-method red mud storage yard adopting the tail-of-reservoir discharge method, the height of the red mud dam refers to the difference between the highest elevation and the lowest elevation of the red mud accumulation body.

2.0.15 total dam height

The height of the red mud dam at the designed final accumulation elevation.

2.0.16 whole storage capacity

The spatial capacity enclosed below the plane of a given dam crest elevation and above the reservoir bottom surface at that dam crest elevation, excluding the volume of the dam body constructed of materials other than red mud.

2.0.17 total storage capacity

The whole storage capacity at the designed final dam crest elevation.

2.0.18 effective capacity

The spatial capacity used for storing red mud below the red mud beach surface and above the reservoir bottom at a given dam crest elevation.

2.0.19 flood regulation storage capacity

The capacity available for storing flood water above the red mud beach surface and below the design flood level at a given dam crest elevation.

2.0.20 red mud beach

The surface layer of the red mud accumulation body formed by discharging red mud slurry or placing red mud filter cake.

2.0.21 length of dry bank

The horizontal distance, at the design flood level, from the intersection point of the water surface of the red mud stacking yard with the red mud beach surface to the intersection point of the red mud beach surface with the upstream slope of the dam.

2.0.22 free height

The height difference between the elevation of the dam crest and the design flood level.

2.0.23 stacking height of red mud

The height difference between the crest of the stacking dam and the crest of the starter dam.

2.0.24 flood regulation height

The height difference between the initial water level of normal flood discharge and the design flood level.

3.1 Basic Design Data and Composition of Design Documents

3.1.1 The design of a dry-process red mud disposal yard should be based on its engineering scale, design stage, project composition and importance, and the following basic design data should be available:

1 Data on the quantity of red mud and the chemical composition and physico-mechanical properties of the red mud;

2 Data of pressure filtration tests on red mud slurry;

3 Data of water quality analysis of the liquid attached to the red mud;

4 Data of hydraulic transport tests or rheological tests on red mud;

5 Data of soil mechanics tests on red mud;

6 Data of red mud dam construction tests;

7 Meteorological and hydrological data;

8 Data of surveying, engineering geological and hydrogeological investigation for the reservoir area of the red mud disposal yard, the dam site, the alignment of the drainage structures, the site of the dam construction materials and the route of the red mud conveying pipes and troughs;

9 Data of geological hazard risk assessment;

10 Seismic data;

11 Data of investigation of the residential areas, important facilities and economy upstream and downstream of the red mud disposal yard;

12 Agreement documents on the land occupied by the red mud disposal yard, the demolition and relocation of buildings and other facilities, and the crossing of railways, highways and navigable rivers by the pipelines;

13 Data of environmental impact assessment.

3.1.2 The design documents provided shall include a description of the design key points and the main drawings exclusively for the use of the enterprise's production management. The description of the design key points and the main drawings shall include the following contents:

1 The design total dam height, total storage capacity and grade of the red mud disposal yard, and the general layout plan and longitudinal profile of the red mud disposal yard;

2 The distribution method and requirements for the red mud disposal yard, the accumulation method and requirements for the red mud accumulation dam, the control of the accumulation slope ratio, the soil covering and vegetation of the dam slope and the drainage requirements; the plan and profile drawings of the red mud accumulation dam;

3 The flood control standards for the different operating periods of the red mud disposal yard and the control standards for the maximum flood level, the minimum safety freeboard and the minimum beach length;

4 The type and dimensions of the flood discharge structures of the red mud disposal yard and the requirements for their operation and sealing;

5 The red mud process parameters: the red mud quantity and particle size, and the red mud moisture content;

6 The drawings of the red mud conveying system and the return water system;

7 The installation and operation requirements for the safety monitoring and environmental protection monitoring systems of the red mud disposal yard;

8 Other contents that shall be described and the attached drawings.

3.2 Site Selection

3.2.1 A dry-method red mud disposal yard shall not be located in the following areas:

1 Scenic and historic areas, nature reserves and drinking water source protection areas;

2 Other areas where the construction of red mud disposal yards is prohibited by state regulations.

3.2.2 The site selection of a dry-method red mud disposal yard shall be determined through technical and economic comparison of multiple schemes, and the following principles shall be complied with:

1 It should not be located upstream of large industrial and mining enterprises, large water sources, important railways and highways, aquatic product bases and large residential areas;

2 It should not be located on the windward side of the prevailing wind direction of large residential areas and the plant area;

3 It shall occupy no farmland or as little farmland as possible, and shall require no relocation of residents or as little relocation as possible;

4 It should not be located above mineral deposits having exploitation value;

5 The catchment area shall be small, the storage capacity shall be sufficient, and the initial and final storage lengths shall be sufficient;

6 The dam construction works quantity shall be small and the production management shall be convenient;

7 Areas with complex geological structures and serious adverse geological phenomena should be avoided;

8 The conveying distance of the red mud slurry shall be short and the conveying energy consumption shall be relatively low.

3.2.3 In addition to complying with the provisions of Article 3.2.2 of this code, the site selection of a slurry dry-method red mud disposal yard shall also satisfy the following conditions:

1 The storage area during the service period of the disposal yard can satisfy the requirements for spreading and sun-drying the red mud slurry;

2 The meteorological conditions are favourable for the drying and consolidation of the red mud slurry, with relatively low rainfall and evaporation is relatively large.

3.2.4 Where two or more red mud storage yards are constructed within the same gully, the interrelationship and mutual influence between the storage yards shall be demonstrated during the design of the later-constructed storage yard.

3.2.5 Where red mud is to be stored in abandoned open-pit mining pits or depressions, a special safety demonstration shall be carried out; where mining activities are being conducted beneath an open-pit mining pit, red mud should not be stored therein.