Pay attention to the problem when dressing

At the end of 2008, affected by the financial crisis, the price of iron ore powder dropped sharply. More iron ore dressing plant because he did not mine, beneficiation process backward, outdated equipment rough, small-scale, low-grade ore, low sales prices, sales difficulties and other reasons, so that enterprises in the edge of small profits and losses. How to make such enterprises develop in the current situation, profitable and competitive, is an important issue facing the leaders of such mineral processing plants.

At this time, we should actively find out the reasons for the existing equipment, carry out system transformation, and improve the taste of iron powder.

First of all, we should look at the problems of raw material crushing and grinding systems.

The particle size of the pre-grinding ore in a small-scale concentrator is about 25 mm, which greatly reduces the grinding efficiency of the mill. Since the mill is a fine grinding device, the grinding efficiency of the 25 mm (mm) ore is less than 80 micrometers (um) when the coarse crushing efficiency of the mill is low. At this time, 1 ton of medium hardness ore needs to consume about 25 KWH. The advanced crushing process has broken the ore to a particle size below 10mm. At this time, the power consumption of the mill grinding 1 ton of ore is only about 13KWH. The method is to add a fine crusher on the crude crushing system of the raw material, so that the particle size of the ore before the mill is reduced from 25 mm to 10 mm, and the crushing of 1 ton of ore by the fine crusher requires 5KWH. Instead of finely crushing the ore with fine crushing equipment before grinding, the power consumption of 1 ton of ore in the two systems of crushing and grinding can be reduced by 7KWH. Moreover, the cost of the hammer liner consumed by the fine crushing equipment before grinding is significantly lower than the cost of the ball mill and the liner. A concentrating plant that processes 100,000 tons of ore per year can use advanced technology in the crushing and grinding process to save electricity and materials consumption by 400,000 yuan.

There are many fine crushing equipments for ore, and there are fewer ideal equipments for users to choose. For example, hammer crushers , whether vertical shaft hammer crushers or horizontal hammer crushers, have short hammer life and hammer. Head and liner consumption, frequent replacement, low output, high power consumption, difficult maintenance and maintenance, long time, low equipment operation rate. The shortest is replaced in three or five days, and the longest is replaced in half a month. The consumption of hammerheads and linings requires 1 yuan for 1 ton of ore and 7 KWH for electricity consumption of 1 ton of ore. We should choose an energy-saving crushing system with low consumption of wear parts, long use time, high output, stable discharge size and low power consumption, such as cone crusher . The power consumption can be reduced from other crusher 7KWH/ton ore. 5KWH / ton of ore. The service life of the lining consumables can be increased from one week to half a year, and the wear-resistant steel such as liners and hammers consumed by crushing 1 ton of ore is about 0.2 kg/ton of ore, which drops to 0.01 kg/ton of ore, and drops nearly 20 times. More than double.

Choose energy-saving, high-yield grinding equipment

1. At present, most of the ball mills we use are main bearings of babbitt alloy bearings. The running resistance is high and the fuel consumption is high. The bearings of large mills need to be equipped with lubrication stations. It is difficult to maintain and maintain the electricity consumption of 1 ton of ore. At 25 kWh (KWH); now the energy-saving ball mill main bearing uses the rolling bearing, the power consumption of grinding 1 ton of ore is about 18KWH. It is lubricated with dry oil and saves more than 80% of lubricating oil annually. The large mill removes the lubrication station of the main bearing, and the maintenance is only required once a year, and the equipment operation rate can reach 100%.

2. The lining plate of the ordinary ball mill adopts strip shape, step shape and large wave type. The disadvantage of these lining boards is that when the lining plate is worn to a certain thickness, it will be bent and deformed, resulting in failure to use; The disadvantage is that the surface shape of the lining plate is simple, the contact area between the steel ball and the lining plate is small, the grinding ability is insufficient, and the grinding efficiency is low, so that the output of the mill is low. It is recommended that you use a double U-shaped lining. The lining has the advantage of being corrugated along the circumferential direction of the mill barrel; there are grooves along the axis of the mill. When the mill is in operation, the grinding body is lifted to a high height, and the contact surface with the lining plate increases the grinding efficiency, and the lining plate has an output of more than 6% than the ordinary grinding machine.

Improve the classification performance of concentrate after grinding, reduce the phenomenon of over-grinding, and improve the grade of concentrate powder

Some concentrators have finely ground the ore powder and directly enter the magnetic separator for magnetic separation. The ball milled ore powder is directly subjected to magnetic separation without being classified, and as a result, the particle size of the ore powder is uneven. The coarse-grained ore grade is low; the fine grade of ore fine is high, but the magnetic field strength is low and the adsorption capacity is poor. As the water flows into the tailings, the grade of the iron concentrate powder is low and the tail running phenomenon is serious. Tips for this kind of mineral processing technology, the milled materials must be grading and screening, and then magnetic separation. Because of the different ores, there is a monomer dissociation particle size at the highest grade. If the particle size is too coarse, the impurities in the ore will not separate, and the grade of the ore will be too low. If the particle size is too fine, the grinding ability and grinding time of the mill will be wasted. Because of the ore particle size below 10μm, the grinding time will increase by 2% for each increase of 1% in the ore powder, and the power consumption and the wear of the steel ball lining will increase by 2%; therefore, do everything possible to reduce the overgrinding minerals. The content is the most effective way to increase mill output, reduce power consumption and increase iron fines recovery. After the group screening measures, the minerals with less than the required particle size are returned to the mill for re-grinding, and the minerals with the required particle size are sent to the selected points in time, which not only improves the concentrate grade, but also improves the grinding efficiency of the mill. .

There are many methods for mineral grading, and the spiral classifier is the most primitive grading device . The grouping method is simple, the classification accuracy is slightly poor, and it is generally applied to the classification of a section of grinding ore discharge products. When the final product size of the iron concentrate is required to be 100% under the sieve of minus 80μm, the first stage classification may adopt a spiral classifier; the second stage classification may adopt a high frequency fine sieve. If the final product particle size of the iron concentrate powder is required to be less than 100%, the proportion of the large particles of the ore particles is relatively small. Under the premise that the screen wear of the high frequency sieve is not serious, the high frequency vibrating screen can be used. The classification is carried out, and the middle ore under the sieve is magnetically selected; the coarse ore on the sieve is returned to the mill for re-grinding. Still another classification device is a hydrocyclone. There are now more large-scale concentrators, removing the one-stage and two-stage spiral classifier equipment and switching to hydrocyclones. This method not only plays a coarse subdivision of the ore powder, but also increases the concentration of the pulp before the magnetic separation and reduces the primary dewatering equipment . The equipment is also graded and concentrated in a dryer before the non-magnetic mineral powder is selected, which has a good effect.

In summary, we have improved the grade of the product by more than 66.5% by carrying out technological transformation, so that it can get a good sales price. Through the technical transformation of equipment, the power consumption of mining machinery will be reduced by more than 25%, and the output will increase by about 30%. The consumption of steel such as lining board, hammer head and steel ball is reduced by more than 15%, which makes the comprehensive economic indicators reach the domestic advanced level, improves the economic benefits of enterprises, increases the competitiveness of enterprises, and creates for the future development and growth of enterprises. good conditions.

Sleeping Bag

A sleeping bag (sleeping bag) is a bag used for sleeping. The vast majority of sleeping bags on the market are labelled with a comfort temperature and an extreme temperature. The comfort temperature is the range of temperatures at which the user sleeps throughout the night, with a maximum and a minimum. The maximum comfort temperature is the kind of heat you feel in a sleeping bag but not when you are sweating profusely, and is generally defined as a sleeping bag with the zip open, arms outside and the head of the bag not tightened, etc.

Development history
Early humans were using animal fur to make warm clothing and sleeping mats, which are still used today, including by the Eskimos living near the Arctic. early 19th century explorers and mountaineers began to test different sleeping bag systems, early sleeping bags were filled with camel hair, which has excellent insulation properties, and then a hollow rubber air mattress was invented and used in the 18th century In 1861 Francis Fox Tuckett tested the first Alpine sleeping bag prototype, and in the mid-1860s the envelope sleeping blanket design began to be perfected, and near the ground are hollow rubber coating as a ground thermal insulation layer.

The role of the sleeping bag is simply to keep heat loss to a minimum, while the body inside the sleeping bag is constantly generating heat to keep warm, the amount of heat generated varies from individual to individual and from situation to situation, all sleeping bag temperature calibration systems are based on a standard human body, but such a standard human body basically does not exist. A sleeping body has approximately 75-100 watts of thermal power, which translates into approximately 47-55 watts per square metre based on the surface area of the body. The amount of energy produced by metabolism is very complex and relates to age, gender and even the amount of fat under the body, but by and large a fit young male always produces far more body heat than an older man or woman. The perception of cold is related to age and experience, with novices generally feeling colder than experienced climbers. People who work outdoors a lot feel warmer in cold conditions than those who work in an office a lot.

Use
Whether it is a down or synthetic cotton sleeping bag, try not to compress it up when it is not in use for a long period of time to keep it as fluffy as possible, and it is good to get a proper tan. The purpose of this is to maintain the nature of down and cotton and extend the life of the bag, especially for down sleeping bags, try to keep them in a special down sleeping bag storage bag (loose breathable cotton bag). As a personal hygiene product, try to avoid borrowing each other's sleeping bags.
When using a sleeping bag there are several ways to improve warmth.
Equip a good quality moisture-proof pad, which is very important, as anyone who camps a lot has experienced, if the cold air goes straight from the ground to the back, that kind of cold is unbearable; drink a hot drink before bed if possible, milk and fruit jelly are fine to warm up the body.
Eat a comfortable meal before bedtime, especially with carbohydrates (starches, sugars).
wearing a long set of thermal underwear and clean socks will be very effective.
wearing more clothes when the sleeping bag is not warm enough, or covering the sleeping bag with clothes and other items.
sharing a tent with a larger number of people.
lighting a gas lamp or cooker in the tent if it is safe to do so.
Build a fire. There are so many ways to do this, so try them out when it matters.