Production of lightweight aggregates from mining and industrial wastes

To prepare concrete by applying industrial or agricultural wastes (energy saving materials) and natural lightweight aggregates, is a new pathway to develop lightweight aggregate concrete. The waste cornstalk, rubber particles made with industrial wastes, polyphenyl granules and natural pumice, as lightweight aggregates, are organically mixed with cement according to certain of proportion, so a kind of new multiphase composite lightweight aggregate concrete was prepared. The research results indicate that the raw materials after pretreatment can form good interfacial bonding with cements, improve further the performances of hardened concrete. The good workability, certain strength and low apparent density of concrete could be guaranteed.

Download Full-text

Bloating Mechanism of Lightweight Aggregates due to Ramping Rate

Advances in Materials Science and Engineering ◽

10.1155/2019/2647391 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Kang Hoon Lee ◽

Jae Hoon Lee ◽

Young Min Wie ◽

Ki Gang Lee

Keyword(s):

Raw Materials ◽

Bottom Ash ◽

Weight Ratio ◽

Lightweight Aggregate ◽

Least Square Method ◽

Dynamic Parameter ◽

Least Square ◽

Industrial Wastes ◽

Recycling Rate ◽

Lightweight Aggregates

The purpose of this study was to improve the recycling rate of industrial wastes by investigating the bloating mechanism of artificial lightweight aggregate depending on the ramping rate and time, which is a dynamic parameter in the production of artificial lightweight aggregate. In this study, coal bottom ash and dredged soil at a weight ratio of 1 : 1 from a domestic power plant were used as raw materials. The artificial lightweight aggregates were formed by using an extruder and pelletizer (φ = 10 mm) and sintered by rapid sintering, 2-step firing, and normal sintering method. The physical properties of the aggregates such as bulk density, water absorption ratio, and microstructure of cross section are investigated with the sintering time and temperature. As the result of bloating and trapping mechanism, black core could be inhibited as the firing time increased at the temperature before surface formation. As a result of firing schedule graphs using least square method, it was possible to manufacture artificial lightweight aggregate with micropores, specific gravity of 1.1, and absorption rate of 3% at a heating rate of 27°c/min or less.

Download Full-text

Preliminary results of the optimization of biogas production at the biogas station of the national research institute of animal production in Grodziec Sląski – Kostkowice

Agricultural science and practice ◽

10.15407/agrisp2.03.026 ◽

2015 ◽

Vol 2 (3) ◽

pp. 26-31

Author(s):

K. Węglarzy ◽

Yu. Shliva ◽

B. Matros ◽

G. Sych

Keyword(s):

Agricultural Production ◽

Crude Protein ◽

Biogas Production ◽

Electric Energy ◽

Corn Silage ◽

Industrial Wastes ◽

Organic Mass ◽

National Research Institute ◽

Digestion Process ◽

By Products

Aim. To optimize the methane digestion process while using different recipes of substrate components of ag- ricultural origin. Methods. The chemical composition of separate components of the substrate of agricultural by-products, industrial wastes, fats of the agrorefi nery and corn silage was studied. Dry (organic) mass, crude protein (fat) fi ber, loose ash, nitrogen-free exhaust were estimated in the components and the productivity of biogas was determined along with the methane content. These data were used as a basis for daily recipes of the substrate and the analysis of biogas production at the biogas station in Kostkowice. Results. The application of by-products of agricultural production solves the problem of their storage on boards and in open containers, which reduces investment costs, related to the installation of units for their storage. Conclusions. The return on investment for obtaining electric energy out of agricultural biogas depends considerably on the kind of the substrate used and on technological and market conditions.

Download Full-text